Recombination of vibrationally cold N2+ ions with electrons.

Recombination of vibrationally cold N2+ ions with electrons was studied in the temperature range of 140-250 K. A cryogenic stationary afterglow apparatus equipped with cavity ring-down spectrometer and microwave diagnostics was utilized to probe in situ the time evolutions of number densities of particular rotational and vibrational states of N2+ ions and of electrons. The obtained value of the recombination rate coefficient for the recombination of the vibrational ground state of N2+ with electrons is αv=0 = (2.95 ± 0.50) × 10-7(300/T)(0.28±0.07) cm3 s-1, while that for the first vibrationally excited state was inferred as αv=1 = (4 ± 4) × 10-8 cm3 s-1 at 250 K.

[The increased sensitivity of dentin: the mechanisms of remineralization using toothpaste with tin fluoride]. / Reshenie problemy povyshennoi chuvstvitel'nosti dentina: mekhanizmy remineralizatsii pri kursovom ispol'zovanii zubnoi pasty s ftoridom olova.

The purpose of the study was clinical and laboratory analysis of the remineralizing properties and clinical efficacy of the course application of the Sensodyne Rapid Relief therapeutic and prophylactic toothpaste for sensitive teeth with tin fluoride. The study involved 50 overwise healthy patients aged from 18 to 25 years diagnosed with a localized form of hyperesthesia of hard dental tissues and no signs of acute inflammation of periodontal tissues. After 7 days of clinical observation and daily use of the toothpaste the hygienic condition of the oral cavity in all patients improved: oral hygiene index was 1.02±0.2 units; gum inflammation index (PMA) - 8.0±1.5%; the absence of hyperesthesia was diagnosed (1 point, p≤0.05). Examination of patients after 14 and 28 days confirmed the absence of pain in 100%, the organoleptic properties of the toothpaste under investigation were also highly appreciated by the participants. A laboratory study showed that patients have an increase in the pH value of mixed saliva and a decrease in its buffer capacity by 13.4±2.25%, which contributes to a more effective remineralizing effect of calcium ions by calcium-binding proteins of mixed saliva. The concentration of fluoride ions in the saliva of patients of both groups increased by average rate of 34±0.5% per week. The combination of tin and fluoride is more effective than fluoride alone. The presence of tin ions causes a higher ability of fluorides to bind with calcium ions on the surface of the dentin and dentinal tubules, inhibits the process of demineralization, enhances the additive interaction of the ions forming the acid-resistant layer on the surface of the dentin and dentinal tubules, leading to a decrease in hyperesthesia of the teeth.

[Further evidence that the serotonin transporter gene is associated with schizotypal traits in a healthy Russian population].

Genetic factors are thought to contribute to schizotypal dimensions. Recently, a number of genetic variants associated with schizotypal traits in psychiatrically healthy people have been found. Authors reported earlier the association between the SERT 5-HTTLPR polymorphism and schizotypal traits measured with MMPI. The present study aimed at the replication of association on a larger sample using other questionnaires and methods of data analysis. The sample comprised 657 people from the Russian population. MMPI, SPQ-74 and TCI-125 were used to measure personality traits. Based on the results of psychological testing, the sample was divided into high risk and control groups. For MMPI, the high risk group included people with the elevation on scale Schizophrenia, for SPQ-74 - people with a total score more than 25 and for TCI-125 - people with lower scores on scale Cooperation and higher scores on Self-Transcendence. In all high-risk groups assessed by different psychological instruments, the frequency of the SS 5-HTTLPR genotype was significantly lower as compared to the corresponding control groups. MANCOVA also showed that individuals with the SS genotype had lower scores on scales related to schizotypal traits. Thus, we have confirmed our previous results on the association between the 5-HTTLPR polymorphism and schizotypal traits in psychiatrically healthy subjects.

[Association between the Val66Met polymorphism of brain-derived neurotrophic factor gene and schizophrenia in Russians].

Recent studies have demonstrated a role of the brain-derived neurotrophic factor (BDNF) in schizophrenia. An association between the Val66Met BDNF polymorphism has been reported but the results of different studies are inconsistent. An aim of the present article is to study the allele and genotype distribution in patients with schizophrenia (783) and mentally healthy controls (633). No statistically significant between-group differences have been found. When the group of patients has been stratified by sex and form of schizophrenia, the higher frequency of the Val/Val genotype is observed in the subgroup of men with continuous (chronic) schizophrenia as compared to men with attack-like form (p = 0.047). Clinical symptoms assessed with the PANSS were more severe in male patients with the Val/Val genotype. The Val66Met polymorphism was not associated with forms of schizophrenia or clinical symptoms in female patients. The results obtained suggest that the association between the BDNF gene and schizophrenia may be related to sex and clinical heterogeneity of disease. The Val/Val genotype is associated with severer form of schizophrenia in men.

Changes in EEG spectral power on perception of neutral and emotional words in patients with schizophrenia, their relatives, and healthy subjects from the general population.

EEG correlates of impairments in the processing of emotiogenic information which might reflect a genetic predisposition to schizophrenia were sought by studying the dynamics of EEG rhythm powers on presentation of neutral and emotional words in 36 patients with schizophrenia, 50 of their unaffected first-degree relatives, and 47 healthy subjects without any inherited predisposition to psychoses. In controls, passive hearing of neutral words produced minimal changes in cortical rhythms, predominantly in the form of increases in the power levels of slow and fast waves, while perception of emotional words was accompanied by generalized reductions in the power of the alpha and beta(1) rhythms and regionally specific suppression of theta and beta(2) activity. Patients and their relatives demonstrated reductions in power of alpha and beta(1) activity, with an increase in delta power on hearing both groups of words. Thus, differences in responses to neutral and emotional words in patients and their relatives were weaker, because of increased reactions to neutral words. These results may identify EEG reflections of pathology of involuntary attention, which is familial and, evidently, inherited in nature. No reduction in reactions to emotiogenic stimuli was seen in patients' families.

[Changes in the EEG spectral power during perception of neutral and emotionally salient words in schizophrenic patients, their relatives and healthy individuals from the general population].

To search for EEG-correlates of emotional processing that might be indicators of genetic predisposition to schizophrenia, changes in EEG spectral power during perception of neutral and emotionally salient words were examined in 36 schizophrenic patients, 50 of their unaffected first-degree relatives, and 47 healthy individuals without any family history of psychoses. In healthy persons, passive listening to neutral words induced minimum changes in cortical rhythmical activity, predominantly in the form of synchronization of slow and fast waves, whereas perception of emotional words was followed by a generalized depression of the alpha and beta1 activity and a locally specific decrease in the power of theta and beta2 frequency bands. The patients and their relatives showed a decrease in the alpha and beta1 activity simultaneously with an increase in the power of delta activity in response to both groups of words. Thus, in the patients and their relatives, reactions to neutral and emotional words were ulterior as a result of augmented reactions to the neutral words. These findings suggest that the EEG changes reflect familial and possibly hereditable abnormal involuntary attention. No prominent decrease in reactivity to emotional stimuli was revealed in schizophrenic families.

[Peculiarities of EEG dynamics in cognitive activity demanding persistent attention in patients with schizophrenia and schizoaffective psychosis and their relatives].

The search for neurophysiologic correlates of attention and working memory dysfunction in families with schizophrenia, 55 patients with schizophrenia and schizoaffective psychosis, 91 unaffected first degree relatives and 48 mentally normal subjects without family history of mental disorders have been studied. Changes in power of 5 EEG frequency bands in 16 records during serial mental arithmetic tasks were analyzed. Abnormalities in EEG reactivity were found both in patients and their relatives. Both groups were characterized by diffuse elevation of delta-rhythm power, the signs of hypoactivation and inversion of reaction asymmetry for different rhythm bands in the frontal area. In relatives, more pronounced attention dysfunction corresponded to more expressed abnormalities in EEG reactivity. Moreover, patients demonstrated insufficient depression of alpha and fast waves activity in the posterior cortex areas relevant to arithmetic activity. The results obtained allow considering an impaired reaction of alpha and fast rhythms inhibition in the posterior cortex areas as characteristic of the disease, and diffuse elevation of delta-waves power and frontal lobe hypoactivation with the inversion of reaction asymmetry as familial features that might reflect an impact of the factors predisposing to psychosis. This predisposition emerged during the cognitive task involving sustained attention and working memory.

[Neuromorphologic and psychological correlates of electrical brain activity in patients with schizophrenia and their relatives]. / Neiromorfologicheskie i psikhologicheskie korreliaty élektricheskoi aktivnosti mozga u bol'nykh shizofreniei i ikh rodstvennikov.

The study aimed at elucidation of potential correlations between EEG features, neuromorphologic and psychological characteristics in patients with schizophrenia and in subjects with familial predisposition to the disease. EEG has been conducted in 71 patients, 162 first-degree relatives of schizophrenia subjects and 67 healthy controls. In the patients and relatives, correlations of power indices for 7 frequency ranges of resting EEG with computed tomography and cognitive parameters were analyzed. The patients revealed negative correlations between slow EEG rhythms and sizes of bodies as well as of posterior horns of lateral ventricules. Positive correlations were shown between expression of alpha- and beta-bands and verbal memory. In the relatives, an increase of slow and fast EEG rhythms power correlated with reduction of sizes of ventricular system regions studied and with deterioration of cognitive indices (mental activity, attention, memory). Overall, the data obtained indicate negative functional consequences of slow and fast EEG rhythms power augmenting in subjects at high genetic risk for schizophrenia, but do not confirm a hypothesis that ventricular enlargement causes EEG slowing in schizophrenia.

[The genetic aspects of the neuropsychology of verbal memory in schizophrenia]. / Geneticheskie aspekty neiropsikhologii verbal'noi pamiati pri shizofrenii.

Genetic study methods were used while examining the families with schizophrenic patients to study the relationships between computerized tomographic and resting ECG parameters with memory for information, which differed in degrees and ways of organization. In patients, memory performance was affected both by genotype-controlled high-frequency alpha-rhythm subranges and by integral delta-rhythm values determined by environmental factors. A significant role of the right hemisphere was found for all forms of remembering. In a group of relatives, predictors of different memory forms differed in frequency and topographic characteristics to a greater degree. These predictors mainly included neuromorphological parameters and power values of alpha-rhythm ranges. Most predictors were under considerable genetic determination.

[A multivariate genetic analysis of the data from a complex study of the predisposition to schizophrenia]. / Mnogomernyi geneticheskii analiz dannykh kompleksnogo izucheniia predraspolozhennosti k shizofrenii.

49 families of schizophrenics (49 probands and their 106 first-degree relatives) were studied by means of psychological methods, EEG and computed tomography. Multivariate genetic analysis were performed to assess genetic and environmental components of parameter phenotypic variance and relations between the parameters and liability to schizophrenia, including formation of discriminant functions for classification of individuals into high risk and normal groups and estimation of the functions heritability. Besides, correlations between parameters of neuromorphological, neurophysiological and psychological levels were calculated. The heritability of most EEG and CT parameters were between 41 and 98%. Among psychological variables only mediated and logic memory seem to be under sufficient genetic control (relatively 62 and 42%). Discriminant functions derived from psychological and EEG parameters, allow to differentiate correctly individuals into high risk and normal groups in 76-88% cases. Results of correlational analysis of psychological and biological variables suggest that there are both system and separate genetically determined abnormalities related to different levels of pathogenesis.

[Genetic analysis of the resting EEG parameters of schizophrenics and their relatives]. / Geneticheskii analiz pokazatelei EEG pokoia bol'nykh shizofreniei i ikh rodstvennikov.

The heritability of the resting EEG parameters was studied in 45 schizophrenic families. In offspring--parent pairs (N = 94) and sibs pairs (N = 27) high correlation of average power values of frequency bands between relatives was found (r > 0.5 for alpha and beta power; r 0.2 to 0.45 for delta and theta power in different electrode placement). Linear discriminate functions (LDF) to separate 1) a control group (N = 20) from healthy relatives (N = 46), 2) control group from relatives with borderline pathology (N = 36) and 3) healthy relatives from relatives with borderline pathology were obtained. True classification is possible in 79%, 81% and 76% cases, heritability coefficients of LDF are 47.7, 64.6 and 57.1% respectively.

Neurophysiological and psychological predictors of genetic risk for schizophrenia.

Mathematical genetic analyses were performed on a sample of schizophrenic families (25 probands and 58 first-degree relatives). Heritability coefficients were estimated for EEG power spectrum parameters and their topography, and also for psychological test data on thought and speech process disorder, designed to assess altered selectivity in cognitive activity. Multiple regression equations for genetic counseling regarding the prognosis of mental illness were derived from the neurophysiological and psychological measures.

[Correlation of the clinical pharmacological action of a single dose of fenazepam with the EEG dynamics and pharmacokinetics]. / Sootnoshenie kliniko-farmakologicheskogo deistviia odnokratnoi dozy fenazepama, dinamiki EEG i farmakokinetiki.

Interaction between the clinical, EEG-effects and phenazepam concentration in the blood was studied in 111 patients with neurotic disorders after intake of the test drug dose (2 mg) administered singly and on the 14th day of the treatment. It was established that EEG changes commonly induced by benzodiazepines supervene primarily within the interval of 1 to 3 h after a single intake which correlates with the maximal degree of the tranquilizing, somnolent and myorelaxant drug action. It was demonstrated that the clinical and EEG-effects occur before attainment of the maximal phenazepam concentration and then become less potent, with preservation of the high blood drug level. Intake of the test dose during the treatment course is characterized, as compared with the effect of a single intake, by less marked clinical action of the drug and the lack of significant changes on the EEG and in the blood phenazepam concentration.

[Relation between the dynamics of EEG indices after a single dose of the tranquilizer phenazepam and its efficacy during a course of treatment of patients with borderline neuropsychological disorders]. / Sviaz' dinamiki pokazatelei EEG posle odnokratnogo priema trankvilizatora fenazepama i ego éffektivnosti pri kurosovoi terapii bol'nykh s pogranichnymi nervno-psikhicheskimi rasstroistvami.

The effect of a single phenazepam dose (1-2 mg) on the power of EEG frequency ranges, their interhemispherical asymmetry and the level of intra- and inter-hemispherical correlations was studied in 78 patients with borderline neuropsychic disturbances divided into four groups depending on the efficiency of phenazepam therapy. Different variants of reactions of EEG parameters related to the characteristics of the clinical action of the drug in different groups of patients were identified. High therapeutical efficacy of phenazepam was associated with a complex of bilateral, relatively generalized changes in power of beta- and alpha-ranges, characteristic of action of benzodiazepins and combined with a predominantly right-side decrease in theta-range and the absence of any significant dynamics of the initially intact correlations of the EEG. Patients with inadequate efficiency of phenazepam showed a topographically-limited and incomplete complex of changes in the power of frequency ranges. They also had alterations in the level of EEG correlation.

[Relation between the effect of tranquilizers and various features of personality structure among patients with borderline states]. / Zavisimost' deistviia trankvilizatorov ot nekotorykh osobennostei struktury lichnosti u bol'nykh s pogranichnymi sostoianiiami.

The authors revealed differences in the clinico-psychopathological structure, therapeutic time-course and efficiency of the treatment by tranquilizers (e. g. phenazepam, a drug whose effect is typical for the entire group of tranquilizers) in 86 patients with borderline states, the nature of differences depending on the typological characteristics of their personality structure. Hypersthenia was associated with a tranquilo-sedative effect while in hyposthenia a tranquilo-stimulating effect was observed. Electroencephalographic examinations also point to various routes of realization of the modulating influence of tranquilizers.