Psychophysiological Assessment of Youthful Motor Vehicle Accident Survivors

Twenty-one children and adolescents (age range 8–17, mean 12.7 years) who had been in motor vehicle accidents (MVAs), and 14 non-MVA controls matched for age and gender, underwent a psychophysiological assessment in which heart rate, systolic and diastolic blood pressure, and skin conductance were measured during baseline and two stressor phases: mental arithmetic and listening to and imagining a MVA like their own. The eight youth who currently met criteria for PTSD or sub-syndromal PTSD significantly reported more subjective distress to the MVA audiotape than the 13 MVA non-PTSD youth or the 14 non-MVA controls. All groups responded physiologically to the mental arithmetic. However, in contrast to expectations, there were no differential physiological responses among the groups to the stimuli reminiscent of the trauma. Possible explanations are explored.     

Features of a Simple Psychophysiological Reaction

The latency of a simple psychophysiological (visual motor) response (SPPR) was studied as dependent on the waiting time, which was the period between the previous response to a subsequent stimulus and was varied from 1 to 3000 ms. An ordinal approximation was used for the resulting monotonic dependence. The latency of the simple psychophysiological response at shorter intervals between the previous response and a subsequent stimulus was observed to be far greater than at longer intervals. The latency decreased with the increasing waiting time until 3–4 s after the previous response. The decrease included at least two components. The components were found to be interdependent. The decrease in latency was assumed to result from autoinhibition due to the previous response.     

A Psychophysiological Study of Affective Disorders in Patients during Post-stroke Rehabilitation

Psychophysiological parameters of affective disorders (depression, depersonalization, and alexithymia) were studied in patients who had suffered ischemic stoke. Significant differences from healthy subjects were observed for certain MMPI scores and EEG, neurophysiological, and neuroimaging parameters. The results provide a basis for better understanding of brain function in healthy people and patients with dysfunction of higher cognitive processes.     

Psychophysiological Characteristics of Nuclear Power Station Operator Activity as a Factor in Accident Rate

Methods of psychological, physiological, and psychophysiological testing were used to assess the intensity of the activity of operators of the power unit control panel of the Khmel'nitskaya nuclear power station. The operators during whose duty serious control errors and preaccident situations were noted were examined. The psychological and psychophysiological characteristics of these operators were shown to differ in that their reactive anxiety was increased and their well-being, activity, and mood scores, as well as the functional reserves of the cardiovascular system and mental and physical working capacity, were decreased. These parameters were considered as criteria in the development of operating measures. It was proposed that not only technological factors but also operators' psychophysiological characteristics in the dynamics of their manifestation be taken into account for elaborating measures of optimal staff selection and placement.     

Explore the Features of Brain-Derived Neurotrophic Factor in Mood Disorders

Objectives

Brain-derived neurotrophic factor (BDNF) plays important roles in neuronal survival and differentiation; however, the effects of BDNF on mood disorders remain unclear. We investigated BDNF from the perspective of various aspects of systems biology, including its molecular evolution, genomic studies, protein functions, and pathway analysis.

Methods

We conducted analyses examining sequences, multiple alignments, phylogenetic trees and positive selection across 12 species and several human populations. We summarized the results of previous genomic and functional studies of pro-BDNF and mature-BDNF (m-BDNF) found in a literature review. We identified proteins that interact with BDNF and performed pathway-based analysis using large genome-wide association (GWA) datasets obtained for mood disorders.

Results

BDNF is encoded by a highly conserved gene. The chordate BDNF genes exhibit an average of 75% identity with the human gene, while vertebrate orthologues are 85.9%-100% identical to human BDNF. No signs of recent positive selection were found. Associations between BDNF and mood disorders were not significant in most of the genomic studies (e.g., linkage, association, gene expression, GWA), while relationships between serum/plasma BDNF level and mood disorders were consistently reported. Pro-BDNF is important in the response to stress; the literature review suggests the necessity of studying both pro- and m-BDNF with regard to mood disorders. In addition to conventional pathway analysis, we further considered proteins that interact with BDNF (I-Genes) and identified several biological pathways involved with BDNF or I-Genes to be significantly associated with mood disorders.

Conclusions

Systematically examining the features and biological pathways of BDNF may provide opportunities to deepen our understanding of the mechanisms underlying mood disorders.     

Age-Related Features of Neuropsychological Disorders in Parkinson's Disease

Parkinson's disease (parkinsonism) is one of the most widespread neurological diseases in the world: 1.5% of the population between the ages of 70 and 79 suffer from it (Huber & Cummings, 1992). Contemporary studies of parkinsonism are not restricted to investigation of the pathogenesis and treatment of motor disorders (tremor, rigidity, hypokinesia, postural disorders): possible disorders in higher mental functions (HMFs) are also analyzed. However, specialists agree on neither the frequency nor the causes of these disorders. The pathogenesis of defects in HMFs has been linked to accelerated aging of the brain (Albert, 1978), to primary biochemical disorders (independent of age), to the effects of drug therapy, to acute and chronic intoxications (carbon monoxide, manganese), to an accompanying atherosclerosis of cerebral vessels, etc. James Parkinson himself, who described this disease, said that disorders of intelligence were not characteristic of it (Parkinson, 1817). The frequency of disorders of HMFs secondary to parkinsonism varies from 4% to 93%, depending on the investigator. The relation of these defects to age is also variously interpreted. Most authors note that the neuropsychological symptoms are more marked and more global if the illness has a late onset (Iakhno, Damulin, & Goncharov, 1992; Huber & Cummings, 1992); but there are data indicating that the tendency toward a buildup of defects is manifested differently depending on which mental function is being examined (Korsakova & Moskvichiute, 1985), and that some disorders (for example, motor disorders) are much more marked in younger patients (Lesser et al., 1979; Mjones, 1949). There is no doubt that disagreements on these issues have to do with differences in the methods used to detect defects and to the methodological approaches to their interpretation.     

Genomic instability in chidren born after the Chernobyl Nuclear Accident (in vivo and in vitro studies)

Analysis of peripheral blood lymphocytes in children born after the accident at the Chernobyl Nuclear Power Plant in the period from 1987 to 2004 (permanent residents of territories contaminated with radionuclides, n = 92; and children of irradiated fathers-liquidators, n = 88) revealed increased levels of aberrant cells (ACs) and aberrations of the chromosomal type as compared to the control (P < 0.05). In three subgroups of children with different initial AC frequencies (children with high AC frequencies, ≥3%; children with medium AC frequencies, 2%; and children with low AC frequencies, ≤1%), the levels of aberrations of the chromosomal type are increased as compared to the control (P < 0.05). The levels of aberrant cells and chromosome aberrations (CAs) in the subgroup of children with ≥3% frequencies significantly differ from those in the subgroup of children with ≤1% AC frequencies. No dependence of the AC and CA frequencies on the year of birth after the Chernobyl accident was revealed. After fractional and single γ-irradiation (137Cs) of blood in vitro in the 10–30 cGy dose range, the average CA frequencies in the first and second mitoses increased in a similar way depending on the initial AC frequencies in the children and parents. All these results suggest an individual character of genomic instability induced by low radiation doses and its transgenerational phenomenon in the organisms of children.     

Characteristic Features of Disorders of the Upright Posture in Patients with Poststroke Hemipareses

Characteristic features of upright posture maintenance and mechanisms of postural disorders in poststroke hemiparetic patients were studied using a bilateral force platform. The following features of postural disorders were revealed in the patients tested: an increase in the velocity and amplitude of the center-of-pressure (CP) sway as compared to in healthy subjects, an absolute decrease in the half-cycles of the CP sway, asymmetry of weight bearing by both feet, and a shift of the center of pressure of an affected foot towards the toe. The disturbance of stability of the vertical posture in such patients is to a greater extent associated with weight-bearing asymmetry. It was shown that the character of the CP sway is mainly determined by a disorder of the sensory motor control, whereas damage to the efferent pathways is responsible for the postural asymmetry. Increase in the muscle tone restricts the sway amplitude. Thus, several forms of postural instability are characteristic of hemiparetic patients. Predominantly sensory, motor, or tonic disorders are responsible for these disturbances of stability.     

Impact of Uncertainties in Exposure Assessment on Estimates of Thyroid Cancer Risk among Ukrainian Children and Adolescents Exposed from the Chernobyl Accident

The 1986 accident at the Chernobyl nuclear power plant remains the most serious nuclear accident in history, and excess thyroid cancers, particularly among those exposed to releases of iodine-131 remain the best-documented sequelae. Failure to take dose-measurement error into account can lead to bias in assessments of dose-response slope. Although risks in the Ukrainian-US thyroid screening study have been previously evaluated, errors in dose assessments have not been addressed hitherto. Dose-response patterns were examined in a thyroid screening prevalence cohort of 13,127 persons aged <18 at the time of the accident who were resident in the most radioactively contaminated regions of Ukraine. We extended earlier analyses in this cohort by adjusting for dose error in the recently developed TD-10 dosimetry. Three methods of statistical correction, via two types of regression calibration, and Monte Carlo maximum-likelihood, were applied to the doses that can be derived from the ratio of thyroid activity to thyroid mass. The two components that make up this ratio have different types of error, Berkson error for thyroid mass and classical error for thyroid activity. The first regression-calibration method yielded estimates of excess odds ratio of 5.78 Gy⁻¹ (95% CI 1.92, 27.04), about 7% higher than estimates unadjusted for dose error. The second regression-calibration method gave an excess odds ratio of 4.78 Gy⁻¹ (95% CI 1.64, 19.69), about 11% lower than unadjusted analysis. The Monte Carlo maximum-likelihood method produced an excess odds ratio of 4.93 Gy⁻¹ (95% CI 1.67, 19.90), about 8% lower than unadjusted analysis. There are borderline-significant (p = 0.101–0.112) indications of downward curvature in the dose response, allowing for which nearly doubled the low-dose linear coefficient. In conclusion, dose-error adjustment has comparatively modest effects on regression parameters, a consequence of the relatively small errors, of a mixture of Berkson and classical form, associated with thyroid dose assessment.     

Impact of Uncertainties in Exposure Assessment on Thyroid Cancer Risk among Persons in Belarus Exposed as Children or Adolescents Due to the Chernobyl Accident

BackgroundThe excess incidence of thyroid cancer in Ukraine and Belarus observed a few years after the Chernobyl accident is considered to be largely the result of ¹³¹I released from the reactor. Although the Belarus thyroid cancer prevalence data has been previously analyzed, no account was taken of dose measurement error.MethodsWe examined dose-response patterns in a thyroid screening prevalence cohort of 11,732 persons aged under 18 at the time of the accident, diagnosed during 1996–2004, who had direct thyroid ¹³¹I activity measurement, and were resident in the most radio-actively contaminated regions of Belarus. Three methods of dose-error correction (regression calibration, Monte Carlo maximum likelihood, Bayesian Markov Chain Monte Carlo) were applied.ResultsThere was a statistically significant (p<0.001) increasing dose-response for prevalent thyroid cancer, irrespective of regression-adjustment method used. Without adjustment for dose errors the excess odds ratio was 1.51 Gy⁻ (95% CI 0.53, 3.86), which was reduced by 13% when regression-calibration adjustment was used, 1.31 Gy⁻ (95% CI 0.47, 3.31). A Monte Carlo maximum likelihood method yielded an excess odds ratio of 1.48 Gy⁻ (95% CI 0.53, 3.87), about 2% lower than the unadjusted analysis. The Bayesian method yielded a maximum posterior excess odds ratio of 1.16 Gy⁻ (95% BCI 0.20, 4.32), 23% lower than the unadjusted analysis. There were borderline significant (p = 0.053–0.078) indications of downward curvature in the dose response, depending on the adjustment methods used. There were also borderline significant (p = 0.102) modifying effects of gender on the radiation dose trend, but no significant modifying effects of age at time of accident, or age at screening as modifiers of dose response (p>0.2).ConclusionsIn summary, the relatively small contribution of unshared classical dose error in the current study results in comparatively modest effects on the regression parameters.     

Effect of Caffeine on Light and Color Sensitivity of the Retina in Healthy Subjects Depending on Psychophysiological Features and Time of Day

In the evening hours as compared to the morning, a mild decrease in the overall state of feeling, activity, and mood was found in young women. More manifest changes were noted in subjects with melancholic temperament. In these subjects, the photosensitivity of the retina was found to be higher; its response to light stimuli in the evening increased to a lesser degree than in subjects with sanguine temperament. Overall, the psychostimulant caffeine slightly increased the response of the retina to light and color stimuli, the effect in the evening being stronger in subjects with melancholic temperament.     

Analysis of risk factors for the formation of internal exposure dose to the rural population and effectiveness of preventive actions in agriculture in the long-term after the Chernobyl Accident

The regularities in the formation of internal exposure doses to the population living in the Chernobyl affected areas are described. The factors responsible for changes in doses are identified and their significance is assessed. The effects of countermeasures on the radiation situation variations are estimated. The need for an addressed application of countermeasures is shown with taking into account types of rural settlements based on the radioecological factors responsible for dose formation in the population.     

Somatosensory evoked potentials in the ventrolateral thalamus

Within the target area (VL) used for the stereotactic treatment of parkinsonian tremor and spasmodic torticollis, electrical stimulation as well as recording of somatosensory evoked potential (SEP) was performed. The effects of stimulation in the target area are facilitation of muscle tone showing some degree of somatotopic distribution. The recorded SEPs indicate a projection of an afferent system (probably of muscle afferents) to the target area. We assume that the target area is a relay station involved in the control of muscle tone. The interruption of muscle afferents in combination with the correct somatotopic localization of the lesion is important for the therapeutic efficacy in parkinsonian tremor and spasmodic torticollis.