Effect of cold stimulation of the arm fingers on the spectral/coherent EEG characteristics in humans

Examination of modifications of EEG in humans induced by cold stimulation of the arm fingers showed that the EEG frequency composition noticeably depended on this thermal influence (in the relaxed state with no movements or during realization of voluntary cyclic movements by the fingers of another arm). In the resting state, cold stimulation mostly induced intensification of the delta activity, while, when coinciding with the performance of voluntary movements, it also resulted in increases in the powers of oscillations of the alpha1 and beta1 ranges. The structure of changes in the coefficients of coherence under the influence of cooling also depended on the conditions of testing (in the resting state or during motor activity). Therefore, the effect of tonic cold stimulation on the interaction between synchronizing and desynchronizing cerebral systems and interrelations between different cortical zones was modified under conditions of realization of a motor function. Neirofiziologiya/Neurophysiology, Vol. 40, No. 3, pp. 268–270, May–June, 2008.     

Fluctuation of energy of spectral components of the EEG signal during dying, clinical death and early period of resuscitation

Fluctuation energy of spectral analysis containing ECG signals were studied in 17 experiments before the modeling of fast death. In the early period of resuscitation ECG recordings were done in 13 orthogonal leads (Frank method). On each lead 5 cardiac cycles were registered with the analysis of 2 components of the ECG: complex QRS and T-wave. In the analyzed period the phase changes for coefficient fluctuations were established. The authors express supposition, that the low meaning of coefficient fluctuations appear in the process of compensation, but high meanings--just like an explosion of compensation.     

Source of F series prostaglandins during the early postpartum period in cattle

In vivo and in vitro studies were conducted to determine the contribution of the bovine uterus to concentrations of 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) in peripheral plasma of postpartum cows. In Experiment 1, cows were assigned to three groups: untreated control (n = 4), hysterectomy following a manually induced prolapse of the uterus (n = 5) and sham operation (n = 3: prolapse of the uterus and replacement). Surgery was performed within 8 h of parturition, and blood samples collected frequently on the day of surgery and once (0800 h) or twice (0800 and 1700 h) daily from Day 1 to Day 15 postpartum. Following hysterectomy, PGFM concentrations decreased precipitously, became essentially undetectable by 5 h, and remained so for the rest of the experimental period. In contrast (P less than 0.01), PGFM concentrations, which remained elevated during the day of surgery in the sham-operated group, peaked on Day 2 (sham-operated group: 1339 pg/ml) or Day 3 (untreated control: 2143 pg/ml), and declined to a basal concentration between Days 10 to 15. In Experiment 2, in vitro metabolism of tritiated arachidonic acid ([3H] AA: 10 microCi) and production of PGF2 alpha and PGFM were studied in explants of early postpartum intrauterine tissues (myometrium, caruncle and intercaruncular endometrium). Extracts of [3H] AA metabolites released into the incubation medium were separated on Sephadex LH-20 column chromatography. Metabolites of [3H] AA, having the same chromatographic mobility as PGF2 alpha, PGFM and PGE2, were detected.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in CNS response to neurotensin accompany the postpartum period in mice

Neurotensin (NT) is a highly conserved neuropeptide in mammals. Recent studies suggest that altered NT neurotransmission in postpartum females could promote the emergence of some maternal behaviors, including offspring protection. Here we evaluated how virgin and postpartum brains from mice selected for high maternal defense differ in response to NT. Virgin and postpartum mice were injected with either vehicle or 0.1 μg NT icv and brains were evaluated for c-Fos immunoreactivity, an indirect marker of neuronal activity. Using ANOVA analysis, common significant responses to NT were found in both female groups in four brain regions, including supraoptic nucleus, ventromedial nucleus, bed nucleus of stria terminalis dorsal, and a subregion of lateral septum (LS). For postpartum mice, only one additional region showed a significant response to NT relative to vehicle, whereas for virgin mice seven unique brain regions showed a significant c-Fos response: nucleus accumbens shell, paraventricular nucleus, central amygdala, and substantia nigra. Using a principal components analysis of c-Fos, we identified regions within each group with highly correlated activity. As expected, virgin and postpartum mice (vehicle conditions) showed different activity hubs and in the postpartum group the hubs matched regions linked to maternal care. The response to injected NT was different in the maternal and virgin groups with maternal mice showing a stronger coordinated activity in periaqueductal gray whereas virgin mice showed a stronger septal and amygdala linking of activity. Together, these results indicate neuronal responses of virgin and postpartum mice to NT and highlight pathways by which NT can alter maternal responses.     

Hemostatic profile during late pregnancy and early postpartum period in mares

Hemostasis is a physiological process that prevents excessive blood loss and represents a protective mechanism at the time of delivery. Peripartum hemorrhage is a recurring hazardous condition to mare's health; therefore, we aimed to study mares' hemostatic profile to investigate whether physiological adjustments occur during late pregnancy and early postpartum. Fifteen pregnant mares have been monitored from the 34th week of pregnancy until the third week after foaling. Fifteen nonpregnant mares were used as control group. Jugular blood samples were analyzed for platelet count (Plt), prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen (Fb). Platelet count showed significant changes at foaling (P < 0.05) and a negative correlation (r = −0.968; P = 0.032) with postpartum. Prothrombin time changed (P < 0.05) showing a significant correlation (r = 0.675; P = 0.016) with late pregnancy. Fibrinogen concentrations changed throughout the experimental period (P < 0.0001). The linear regression model revealed a positive correlation (r = 0.9210; P < 0.0001) between Fb and late pregnancy and a negative correlation (r = −0.9583; P = 0.042) between Fb and early postpartum. The shortening in PT recorded in the imminence of parturition along with the increase in Plt and Fb at foaling might reflect a physiological hypercoagulable state that constrains excessive bleeding, enhancing mares' odds of surviving. Our research improves the knowledge about blood coagulation in periparturient mares providing specific information on routine coagulation tests that may support in monitoring mare's hemostatic profile during late pregnancy and early postpartum.     

Sleep,daily activity rhythms and postpartum mood: A longitudinal study across the perinatal period

Women with a diagnosis of bipolar and major depressive disorders are at higher risk to develop postpartum depression. The primary objective of this longitudinal study was to determine whether daily activity rhythms and sleep parameters differ between women with and without a history of a mood disorder across the perinatal period. A secondary objective was to determine whether changes in these parameters were associated with postpartum mood. In total, 33 women were included in this study, 15 of which had a history of a mood disorder (high-risk group) and 18 who did not (low-risk group). Sleep and daily rhythms were assessed subjectively and objectively during the third trimester (≥26 weeks gestation) and again at 6–12 weeks postpartum. Mood was also assessed at both time points. Women in the high-risk group showed greater subjective daily rhythms and sleep disturbances across the perinatal period. Objective sleep efficiency was worse in the high-risk group in the postpartum period. Changes in both subjective daily rhythms and objective sleep efficiency were predictive of changes in depressive symptoms across the perinatal period. These findings encourage the development of preventative therapeutics to ensure circadian rhythm and sleep stability throughout the perinatal period.     

First ovulation and ketone body status in the early postpartum period of dairy cows

The effect of ketone body status on occurrence of first ovulation during early lactation was assessed in 84 multiparous dairy cows under field conditions. Animals were equally distributed across 8 farms and were controlled by the same herd fertility monitoring program. Cows were visited twice antepartum and 6 times postpartum at weekly intervals between 5:30 and 8:30 AM. On these occasions, body condition scores and milk yields were measured, blood and milk samples were taken, cows were gynecologically examined, and parameters of reproduction were determined. The onset of first ovulation was specified by milk progesterone determination and rectal palpation. Cows starting postpartum ovarian cyclicity within or after 30 d were classified as early and late responders (ER and LR, respectively). Resumption of the estrous cycle within 30 d postpartum is considered optimal under practical conditions, and classification based on this threshold value resulted in groups of equal size and equal distribution of ER + LR cows within farms. Ketone bodies measured were beta-hydroxybutyrate in serum and acetoacetate and acetone in serum and milk. Blood serum and milk ketone body concentrations during the first 6 wk of lactation were higher in LR than in ER, whereas plasma glucose and nonesterified fatty acid and milk fat, protein and urea concentrations did not differ between groups. Maximal concentrations of ketone bodies from parturition to first ovulation were better predictors of the onset of the estrous cycle than mean or minimal concentrations over the same period. Milk acetone and serum beta-hydroxybutyrate concentrations provided the most reliable information with regard to resumption of ovarian activity of all ketone bodies.     

Classification of the adolescent EEG by the spectral and segmental characteristics for normals

The 16-channel EEG records of 45 adolescents with schizophrenia and 39 healthy adolescents were subjected to statistical combinatorial analysis of 160 elementary EEG characteristics (6 spectral and 4 segmental EEG characteristics for a channel). Employing pattern recognition algorithm "Kora-n", a list of 37 combined EEG patterns was compiled. This list characterized with a minimal error the EEG of healthy adolescents in such a way that none of these characters featured the EEG of adolescents with schizophrenia. Analysis of this list of EEG characteristics suggests that the contrast between EEG of healthy and ill adolescents is the sharpest in the F4, Cz, T3 and O1 derivations. Compared to EEG samples of schizophrenic subjects, EEGs of healthy subjects exhibit lower levels of delta and theta activity mainly in the frontal and temporal regions of the cortex and higher level of alpha activity predominantly in the occipital region. Applicability of the list of EEG patterns for diagnostics of schizophrenia-type disorders of adolescents is discussed.     

Amniotic fluid and blood lactate concentrations in mares and foals in the early postpartum period

Amniotic fluid (AF) lactate concentration and time-dependent changes in blood lactate concentration in mares after parturition have never been evaluated. In this study, the venous blood lactate concentration of mares and foals during the first 72 h of the postpartum period was assessed, and the concentration of lactate in the AF collected during delivery and the utility of its measurement for evaluating the foal's health were investigated. This prospective observational study was carried out on mares attended at delivery. They were divided into mares delivering healthy (Group 1) and sick (Group 2) foals. The following samples were collected: AF and umbilical blood at delivery, mare's and foal's jugular blood every 12 hours from parturition until 72 h postpartum (T0-T72). Sixty-two mares were enrolled in Group 1 and 19 in Group 2. In Group 2, the survival rate was 68.4%. The median blood lactate of the foals at T0 was 3.60 mmol/L in Group 1 and 5.05 mmol/L in Group 2. The monitoring of the blood lactate concentration showed a significant time-dependent decrease from T24 in the foals (P < 0.01) and from T12 in the mares (P < 0.01). Lactate concentration over time was significantly different between healthy and sick foals (P < 0.01) but not between mares with normal and dystocic delivery (P = 0.08). A significant difference (P = 0.04) was detected as regards AF lactate concentration between Group 1 (median 14.99 mmol/L) and Group 2 (median 12.61 mmol/L). For the first time, AF lactate concentration was evaluated during parturition, and significantly higher levels were found in mares delivering healthy foals. This was an unexpected and very interesting result which warrants further investigation involving a larger number of mares. Additional studies are needed before either mare's blood or AF lactate concentration can be used in a clinical setting.     

Relations of the EEG local and spatialtemporal spectral characteristics changes under hypoxia in humans

Spatial temporal and local EEG characteristics were studied in healthy subjects during inhalation of hypoxic oxygen-nitrogen gas mixture with 8 % content of oxygen. Analysis of spectra power density, coherence, phase shift, similarity of dominant frequencies in the EEGs of different derivations was performed separately for the EEG epochs with and without visually detected patterns of spatial synchrony of the EEG. Apart from this, a fact of dominance of the frequency in the EEG spectra of corresponding derivation was taken into account when estimating spectral parameters. Results of the study showed that, in general, under hypoxia, the EEG coherence in alpha- and delta-frequency range decreases as compared to the background level, in beta-range growth of this parameter is observed, in theta-range ambiguous changes occur: in the epochs with patterns of spatial synchrony--growth, in other epochs--lowering. Under hypoxia, also occurs growth of frontal and temporal EEGs' phase shift (corresponding to EEGs other derivations) in delta- and theta-range. In beta-range, on the contrary, average level of the phase shift decreases. It was revealed that taking into account the fact of dominance of frequency in the local EEG spectra is necessary for correct interpretation of the EEG spatial and temporal parameter analysis' results. A mathematical model of interaction between processes with different frequency characteristics is suggested, which explains some facts obtained in the study.     

EEG changes in the early postoperative period after excision of tumors of basal-diencephalic location

Changes in the EEG spectral coherence characteristics were analyzed in 60 patients in the early postoperative period after the excision of basal-diencephalic tumors (located in the hypothalamic and thalamic structures) using different surgical approaches (transcallosal, subfrontal, and transnasal). On the first day after surgery, all the patients exhibited a significant decrease in the Δ, θ, and α rhythms compared to the preoperative recordings. Decreased interhemispheric and increased intrahemispheric coherent relations were found simultaneously with changes in the EEG power in patients operated on through the transcranial approach. Within 7–10 days, the pathological structure of the functional relations changed reciprocally. In the case of the transnasal approach, the patients exhibited only an impairment of interhemispheric interaction in the frontocentral areas on the first day after surgery. A decrease in the interhemispheric and an increase in the intrahemispheric coherent relations were determined by the irritation of the pathologically changed hypothalamic and thalamic structures, rather than the dissection of the corpus callosum.     

Self-efficacy and the promotion of health for depressed single mothers

Single mothers are a vulnerable population at risk for poor mental and physical health. This paper discusses the mental and physical health of single mothers, as well as the psychosocial and socio-economic risk factors placing single mothers at risk for poor health outcomes. Some of these include, gender, income level, educational status, social support, stress and certain personality characteristics. Theoretical models with the potential to explore ways to promote health in depressed single mothers will also be presented. The paper concludes with the application of these models to primary prevention and the promotion of health for single mothers along with recommendations for future research.