Protein kinase C alterations in aortic vascular smooth muscle cells from rats with cirrhosis

It was found that the frequency of extreme situations (traumas, deaths, sudden diseases) in miners working in Spitsbergen mines (74 degree N) correlates well with heliogeomagnetic activity (local magnetic disturbances, solar proton flashes). It was shown that in winter, both an enhanced and an extremely low level of magnetic activity can affect the occurrence of extreme situations. The results obtained can be used for predicting and reducing the frequency of extreme events in the zone of the polar cap during geomagnetic disturbances.     

Cisplatin- and paclitaxel-induced apoptosis of ovarian carcinoma cells and the relationship between bax and bak up-regulation and the functional status of p53

A complicated nonlinear biological system should be in principal more sensitive to the external factors activity including geomagnetic disturbances. The complex of experimental studies based on this hypothesis were done simultaneously in two hospitals in Moscow as well as in condition of space orbital station, where just above-mentioned conditions are the case. This studies revealed that the reaction of astronauts to the geomagnetic storm involves a mobilization and activation of all centers of the sympathetic link, and as a result,--a significant increase and stabilization of pulse (heart rate), decrease of the heart rhythm variability and the power of respiratory waves. This nonspecific adaptation stress-reaction was accompanied by variations in the regulation of vascular tonus which is correspond to specific adaptation stress-reaction. The results of clinical examinations of healthy people and patients with the ischemic heart disease lead us to the conclusion that the reaction to the geomagnetic disturbances are mainly of one type and manifests themselves in deterioration of the physiological status, rheologic blood characteristics and the heart rate disturbances similar to ones observed in astronautes.     

Dietary risk factors for colon cancer in a low-risk population

Spontaneous EEG was registered under different activity conditions in 26 volunteers. The EEG synchronisation parameters were compared with the geomagnetic and solar activity on the day of experiment. A positive correlation of the EEG data with the geomagnetic activity was revealed, being most obvious in the frontal and central areas. A negative correlation between some local EEG synchronisation parameters and different indices of the solar activity, was also revealed. The degree of synchronisation of the spontaneous EEG seems to reflect sensitivity of the human nervous system to the Earth's magnetic field. A stressor response to strong short-term disturbances in the geomagnetic field reveals itself in the form of enhancement of the EEG global synchronisation. A sedative effect of slow magnetic oscillations is locally revealed in the parameters of the EEG synchronisation within the left hemisphere as well as the interhemisphere synchronisation.     

Pathologic classification of prostate carcinoma: the impact of margin status

Analysis of experimental data demonstrates that cosmic ray enhancement stimulates an increase of atmospheric aerosols and cloudiness. The study of solar proton events (SPE) has shown that during SPE one can observe increase in aerosol density by 1.2-1.4 times at 12-18 km altitudes. Such variations of aerosol density can be detected on global scale. Aerosol variations cause changes in integral atmospheric transparency which during disturbed periods can reach 5-6%. The atmospheric integral transparency variations are not less during the solar cycle on account of galactic cosmic ray variations. Atmospheric transparency variations creating the so-called "grey filter" for solar radiation should lead to surface temperature variations. During the periods of low solar activity under the influence of enhanced galactic cosmic ray fluxes, the density of the "grey filter" should increase and cause a decrease in surface temperatures, correspondingly. In frame of the physical mechanism considered the connection between solar cycle durations and surface temperature variations can be explained. In addition, one can understand the physical reason for the "Little Ice Age" appearance during Maunder minimum of solar activity, 2400 years periodicity of climatic processes, strong influence of the decrease in main geomagnetic field intensity on the development of Ice Age and Global Cooling.     

In vitro enhancement of p38 mitogen-activated protein kinase activity by phosphorylated glia maturation factor

We previously demonstrated that glia maturation factor (GMF), a 17-kDa brain protein, can be phosphorylated in test tube by several protein kinases, and that endogenous GMF is rapidly phosphorylated upon stimulation of astrocytes by phorbol 12-myristate 13-acetate. We further observed that protein kinase A (PKA)-phosphorylated GMF is a potent inhibitor (IC50 = 3 nM) of the ERK1/ERK2 (p44/p42) subfamily of mitogen-activated protein (MAP) kinase. We now report that, by contrast, PKA-phosphorylated GMF strongly enhances the activity of a related but distinct subfamily of MAP kinase, the p38 MAP kinase, showing an increase of 60-fold over baseline and an EC50 of 7 nM. Non-phosphorylated GMF or GMF phosphorylated by other kinases exhibits only minimal effect. The intracellular interaction of PKA, GMF, and p38 is supported by the phosphorylation of GMF upon cellular stimulation by forskolin (blocked by PKA inhibitor) and by the co-immunoprecipitation of p38 with GMF from cell lysates. Withdrawal of nerve growth factor from PC12 leads to increased GMF phosphorylation with a time course similar to that reported for p38 activation. The results correlate well with a previous report that ERK and p38 carry out opposing functions and implicate GMF as a regulator of major cellular events.     

Outline of chronohygiene

Since chronotherapy already manipulates rhythmical functions, it is the important task of chronohygiene to outline the object of therapy i.e. health, from chronobiological points of view. Only on such a basis can chronohygiene be extended to the preventive provisions of health care and health education in regard to the biological time structure. Health can be characterized as an optimal state of harmonious time structure and its integration into the temporal orders of the environment. The circannual variations of an organism establish a seasonal risk cycle changing the inner preconditions of therapy as well. Moreover, chronohygiene must raise the question of whether the biological circannual rhythm is an integrating component of the human time organization, or if it may be levelled by civilization. Circadian variations of the organism not only modify the preconditions of therapy, but in particular those of activity and efficiency. The nocturnal maximum of functional economy normally is protected against exploitation by a simultaneous minimum of vigilance, which provides the nightly recovery. Therefore the destruction of this phase relationship by night-work must worsen recovery conditions. The disturbance of the time structure in the organism by night-work not only affects the circadian system, but faster rhythms as well. The phase position of the circadian rhythms is closely related to the individual responsiveness of the autonomous system as well as to the pulse-respiration-ratio. The latter can serve as a chronobiological criterion for evaluating suitability or risk of night- and shift-work. The effort of chronohygiene is based on the fact that disturbances of the time structure represent just a complementary aspect to disturbances of the spatial structure of the organism.     

Psychopathologic symptomatology and its prognostic value in the acute period of right hemisphere strokes

In order to evaluate the possible psychopathological symptomatology the authors analyzed the results of a clinico-dynamical observation of 176 patients in the acute period of a stroke. Among 128 patients with the right hemisphere localization of the focus (the main group) in 60 cases (47%) there were revealed psychopathological symptoms whereas in the control group (48 cases) with left hemispheric foci only 2 patients (4.2%) such disturbances were noted. The main expressions of psychopathological syndromes in patients with lesions of the right hemisphere were anosognosia, certain emotional reactions in the form of euphoria, a drop in purposeful activity, motor and mental aspontanity and specific confabulatory disorders. The qualitative and quantitative specificity of psychopathological syndromes in focal vascular lesions of the right hemisphere is supplementary material for further deep studies of the functional asymmetry of the brain hemispheres.     

Autonomic components of voluntary reaction in children with different ratios of direct and verbal stimuli

Interconnection between effector vegetative components of voluntary activity in children (6 to 7 years) has been studied on a model of arithmetic count with a different ratio of direct (kinesthetic, visual) and verbal stimuli. It has been shown that perception and processing of direct signals set up optimal conditions of vegetative providing for voluntary activity in children. A statistically significant correlation has been found between the characteristics of interconnection of vegetative components (relationship betwpen the heart rate and arterial pressure) and the level of capacity for mental work ("efficiency coefficient"). This dependence suggests that the neurodynamics in vegetative providing for voluntary reactions reflects the functional state of higher integrative brain activity in children.     

Mobile phones modulate response patterns of human brain activity

Mobile phones emit a pulsed high-frequency electromagnetic field (PEMF) which may penetrate the scalp and the skull. Increasingly, there is an interest in the interaction of this pulsed microwave radiation with the human brain. Our investigations show that these electromagnetic fields alter distinct aspects of the brain's electrical response to acoustic stimuli. More precisely, our results demonstrate that aspects of the induced but not the evoked brain activity during PEMF exposure can be different from those not influenced by PEMF radiation. This effect appears in higher frequency bands when subjects process task-relevant target stimuli but was not present for irrelevant standard stimuli. As the induced brain activity in higher frequency bands has been proposed to be a correlate of coherent high-frequency neuronal activity, PEMF exposure may provide means to systematically alter the pattern fluctuations in neural mass activity.     

Mutations in CLCN5 chloride channel in Japanese patients with low molecular weight proteinuria

It was hypothesized based on previous laboratory observations and theoretical concepts that astronauts working at the "Mir" station under zero gravity conditions exhibit enhanced sensitivity to geomagnetic disturbances. The result of studies made it possible to reveal the dynamics of changes in cardiovascular characteristics separately in the main phase and the phase of storm restoration. A similar dynamics of cardiac activity was observed in experimental rabbits during geomagnetic storms.     

Sudden unexpected death in epileptics following sudden, intense, increases in geomagnetic activity: prevalence of effect and potential mechanisms

Abrupt, intense increases in global geomagnetic activity during the local night may precipitate a significant proportion of sudden unexpected (or unexplained) deaths (SUD) in epileptics. Over a 2-year period SUD in healthy chronic epileptic rats occurred when the average daily geomagnetic activity exceeded 50 nT (nanoTesla) and suddenly began during local night. Other experiments demonstrated that epileptic rats displayed more spontaneous seizures per night if there had been sudden increases in geomagnetic activity. Analyses of previously published data indicated that the number of SUDs/month in a population of human epileptics was positively associated with the number of days/month when the average geomagnetic activity exceeded 50 nT. The results support the hypothesis that suppression of the nocturnal concentrations of the endogenous anticonvulsant melatonin by sudden increases in geomagnetic activity may encourage fatal cardiac arrhythmias by uncoupling the insular/amygdaloid-paraventricular hypothalamic-solitary nucleus pathways.     

SPECT and PET in neurobiology

PET (positron emission tomography) and SPECT (single photon emission computed tomography) are isotopic methods in which the distribution is registered of radiolabelled tracers given in such small amounts that they are without effect on the organism or the organism's disposal of them. Thus, a series of important biological processes in the intact organism can be studied. The methods have been used in many disciplines but in particular for neurobiological research on the brain--e.g., the brain's regional blood circulation and mapping of the brain's functional structure. The methods have also been used in the investigation of glucose and amino acid metabolism in the brain and receptor conditions.     

Interpreting functional imaging studies in terms of neurotransmitter cycling

Functional imaging experiments, in particular positron-emission tomography and functional magnetic resonance imaging, can be analyzed either in psychological terms or on the basis of neuroscience. In the usual psychological interpretation, stimulations are designed to activate specific mental processes identified by cognitive psychology, which are then localized by the signals in functional imaging experiments. An alternate approach would be to analyze experiments in terms of the neurobiological processes responsible for the signals. Recent in vivo 13C NMR measurements of the glutamate-to-glutamine neurotransmitter cycling in rat and human brains facilitate a neuroscientific interpretation of functional imaging data in terms of neurobiological processes since incremental neurotransmitter flux showed a 1:1 stoichiometry with the incremental rate of glucose oxidation. Because functional imaging signals depend on brain energy consumption, a quantitative relationship can be established between the signal (S) and the specific neurochemical cerebral neurotransmitter activity (N) of glutamate-to-glutamine neurotransmitter cycling. The quantitation of neuronal activity proposed has implications for the psychological design and interpretation of functional imaging experiments. Measurements of the neurotransmitter cycling flux at rest in functional imaging experiments suggest that performing cognitive tasks and sensory stimulations increases neurotransmitter cycling by only 10-20%. Therefore it cannot be assumed that reference state activities are negligible, nor that they are constant during stimulation.     

Stability of Periodically Unsteady Axisymmetric Jet

To date, the majority of studies on stability of axisymmetric jets have been completed under the assumption of steady mean flow. Yet, many of the natural and man-made flows that are modeled by these jets can have an inherent unsteadiness; the effects of which on the stability and transition have not been determined. Moreover, controlled unsteadiness can be used to control stability and possibly the transition to turbulence. In this note, the effects of periodic variations of the mean flow on the stability of axisymmetric jets are examined. The problem is treated analytically. The results show that the governing equations and dispersion relation for the unsteady jet can be reduced to those governing the steady jet with a time transformation. It is shown that the periodic variations in the mean flow cause amplitude and phase modulations of the unstable modes. The implications of the modulations on the subsequent transition stages are discussed.     

Experimental Study of Ice Jam Formation Dynamics

Ice jams pose a significant threat to human safety and property and represent one of the most dynamic of river ice processes. A key limitation in the advancement of knowledge of ice jam formation is the lack of quantitative data describing these dynamics, which is essential also for validation of advanced computational models. In this study, an experimental investigation of ice jam formation under steady carrier discharge was undertaken. Thus, unsteady effects were entirely due to the ice jam formation process itself. Quantitative data describing the variation in discharge, ice jam thickness, water level variation, and ice cover progression provides unprecedented data describing the dynamics of ice jam formation. While the processes of ice jam formation are indeed dynamic, the results of this investigation suggest that the analysis of ice jams formed under steady carrier flow conditions may be adequately handled by the usual steady flow ice jam stability relationships. The applicability of the popularly applied wide jam theory approach to modeling ice jams is further supported by this investigation.     

Somatotopy in the human motor cortex hand area. A high-resolution functional MRI study

Fine-scale somatotopic encoding in brain areas devoted to sensorimotor processing has recently been questioned by functional neuroimaging studies which suggested its absence within the hand area of the human primary motor cortex. We re-examined this issue by addressing somatotopy both in terms of functional segregation and of cortical response preference using oxygenation-sensitive magnetic resonance imaging at high spatial resolution. In a first step, spatial representations of self-paced isolated finger movements were mapped by using motor rest as a control state. A subsequent experimental design studied the predominance of individual finger movements by using contrasting finger movements as the control task. While the first approach confirmed previous reports of extensive overlap in spatial representations, the second approach revealed foci of differential activation which displayed an orderly mediolateral progression in accordance with the classical cortical motor homunculus. We conclude that somatotopy within the hand area of the primary motor cortex does not present as qualitative functional segregation but as quantitative predominance of certain movement or digit representation embedded in an overall joint hand area.     

Neuropsychological indexes of a partial frontal syndrome in patients with nonfrontal gliomas.

33 brain tumor patients (aged 26–74 yrs) were investigated with quantitative and qualitative neuropsychological assessments, systematic behavioral observations, and recordings of regional cerebral blood (rCBF). Ss with supratentorial highly malignant gliomas showed severe disturbances of attention, lack of control over premotor and executive functions, distractibility, a deficient abstract attitude, a loss of speech initiative, and diminished speech production. Such impairments are associated with functions of the frontal lobe system and may be related to frontal functional cortical changes as mirrored by rCBF. Signs of frontal dysfunction were seen in Ss with nonfrontal tumors and may suggest frontal lobe diaschisis in patients with Grade III–IV astrocytomas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A neutral N-methyltransferase activity in the striatum determines the level of an endogenous MPP+-like neurotoxin, 1,2-dimethyl-6,7-dihydroxyisoquinolinium ion, in the substantia nigra of human brains

An endogenous MPTP-like dopaminergic neurotoxin, N-methyl(R)salsolinol, increases in the parkinsonian cerebrospinal fluid and accumulates in the human nigro-striatum. An N-methyltransferase specific for (R)salsolinol was found in human brain with optimal pH at 7.0 and 8.5. The correlation of the enzyme activity with the level of N-methyl(R)salsolinol and its oxidation product, 1,2-dimethyl-6,7-dihydroxyisoquinolinium ion was examined in the brain regions. Neutral N-methyltransferase activity in the striatum was found to correlate with the level of the endogenous MPP+-like isoquinolinium ion in the substantia nigra (P < 0.001). Considering that this neutral N-methyltransferase activity increases in parkinsonian lymphocytes, the enzyme may be an endogenous factor in the pathogenesis of Parkinson's disease.     

Sequence, exon-intron organization, transcription and mutational analysis of prnA, the gene encoding the transcriptional activator of the prn gene cluster in Aspergillus nidulans

Rate coding and temporal coding are two extremes of the neural coding process. The concept of a stationary state corresponds to the information processing approach that views the brain as a decision maker, adopts rate coding as its main strategy and endorses the single- or few neuron approach. If information derived from sensory stimulation is used to continuously update the brain's internal representation of the world, then neural codes may change with time through learning. As a consequence, the same spike sequence may be interpreted differently (or evoke a different behavior) later in the day. This non-stationary viewpoint is embodied in the representational model of brain function that stresses learning and plasticity and employs temporal coding in neural assemblies. We argue that the switching between quasi-stable brain states as a result of learning is more relevant than the neuronal patterns, and the correlations between them, that are found during stationary states. The neural code likely resides in the activity patterns that cause this state-switching.     

Do geomagnetic disturbances of solar origin affect arterial blood pressure?

OBJECTIVE: Episodic reports suggest that geomagnetic disturbances of solar origin are associated with biological and clinical events, including increased arterial blood pressure (BP). We reassessed this aspect by relating solar activity levels to ambulatory BP measured in our out-patient population. PATIENTS AND METHODS: The ambulatory BP measurements of 447 consecutive untreated patients attending a hypertension out-patient clinic who did a monitoring for diagnostic purposes over 5 years were retrieved. The mean daytime, night-time and 24-h BP and heart rate values were related to the temporally corresponding geomagnetic index k-sum obtained by the nearest observatory. K-sum is a local measurement of the irregular disturbances of the geomagnetic field caused by solar particle radiation. RESULTS: Significant to highly significant positive correlations were observed for k-sum with systolic (daytime and 24 h) and diastolic BP (daytime, night-time and 24 h), but not with heart rate. No correlations were found with the k-sum of 1 or 2 days before the monitorings. Multiple correlations which also included other potential confounding factors (date, age) confirmed a significant effect of k-sum on BP. Comparison made in season-matched subgroups of quiet and disturbed days (using three different criteria of definition), always showed significantly higher values in the disturbed days for all BP parameters except systolic night-time pressure. The difference between the quietest and the most disturbed days was of about 6 to 8 mm Hg for 24-h systolic and diastolic BP. CONCLUSION: These results are unlikely to be due to unrelated secular trends, but seem to reflect a real relation between magnetic field disturbances and BP.