Effects of different electrodes on bioelectrical impedance values

Effects of different electrodes on bioelectrical impedance values measured by the Selco bioelectrical impedance plethysmograph (SIF-881, Japan) were investigated using 8 adult females (age: 35.3 +/- 7.6 yr, Ht: 156.9 +/- 3.8 cm, Wt: 57.1 +/- 9.9 kg, and hydrodensitometrically determined body fat: 29.4 +/- 6.0%). The Lectec MP3000 electrode (Liberty Carton, USA) and the Bipolar electrode (Sanwa, Japan) produced significantly higher impedance values when compared to the Disposable electrode (Adovance, Japan) and the ECG electrode (Nihon Kohden, Japan). The coefficient of variation was significantly lower for the Disposable electrode (0.8%) and the ECG electrode (0.2%) than that for the Lectec MP3000 electrode (2.3%) and the Bipolar electrode (4.9%). In conclusion, the ECG electrode provides higher bioelectrical impedance values with the highest reproducibility in the assessment of human body composition by the bioelectrical impedance plethysmography.     

The effect of amniotic fluid taken from women in labor on the morphofunctional development of fetal and newborn rats]

Amniotic fluid from women was injected intra-amniotically to rats at the 14th day of pregnancy in a dose 0.3 ml. Morphological and functional parameters of embryonic development of rats and EMG activity of rat puppies at the age of 30-34 days differed from control ones with respect to the degree of maturity and motor disturbances of newborn babies. The data obtained reveal not only evident but also masked forms of motor pathology which was observed in children later, namely to 6-9 months. Chronic motor pathology in rat puppies was unilateral with central motor disturbances in babies being directly related to the degree of these disturbances.     

Interrelationship between the neocortex and limbic system in emotional stress and epileptiform syndromes

The paper describes bioelectrical correlates of negative emotional states on three models: 1) states caused by local, chronic electric stimulation of negative emotiogenic zones (in cats, rabbits); 2) by a neurogenic stress in rats resulting from a conflict of afferent excitations; 3) by an experimental syndrome--"expectation stress". The data attest that hypersynchronization of bioelectrical activity in limbic and cortical structures is a sufficiently significant correlate of an emotional stress. It is assumed that hypersynchronization reflects one of the general mechanisms of involvement of brain structures in a state of neurogenic stress and its manifestation.     

Description and validation of an ECG removal procedure for EMGdi power spectrum analysis

We describe a cross-correlation procedure for removing contaminating electrocardiogram (ECG) complexes from the diaphragmatic electromyogram (EMGdi). First, the operator selects ECG templates from the EMGdi signal during expiratory intervals. Second, these templates are used to locate ECG complexes occurring during inspiratory EMGdi activity. Third, at the point of maximum correlation between the template and these ECG complexes, the template is adjusted in size and offset to "match" the ECG complex, and adjustments are determined by the linear regression coefficients. Finally, the modified template is subtracted from the EMGdi signal. To evaluate our method, we compared the power spectral density (PSD) obtained from processing EMGdi signals by our method with those obtained from the EMGdi signal in which ECG complexes had been removed by gating. Our results indicate that PSD obtained by these two different methods shows no statistically significant differences with respect to the following features: centroid frequency, median frequency, total power, standard deviation, skewness, and kurtosis.     

The role of the dopamine and noradrenaline systems in regulating autogenic motor activity in rat pups

In experiments on 3-day rat puppies, studies have been made of the effect of a stimulator of noradrenaline receptors--clonidine, and a stimulator of dopamine receptors--apomorphine on autogenic motor activity. It was shown that clonidine injections result in a significant increase of this activity, whereas apomorphine slightly decreases the latter. The data obtained in the present work together with those described earlier for l-DOPA effects, suggest that double regulation of autogenic activity is realized at early stages of ontogenesis. This regulation includes excitatory noradrenergic mechanisms and inhibitory influences which are mediated presumably by dopaminergic systems of the brain.     

K-means algorithm for the detection and delineation of QRS-complexes in Electrocardiogram

Electrocardiogram (ECG) is an important bioelectrical signal used to asses the cardiac state of a patient. It consists of a recurrent wave sequence of P-wave, QRS-complex and T-wave associated with each beat. The QRS-complex is the prominent feature of the ECG. This paper presents a simple method using K-means clustering algorithm for the detection of QRS-complexes in ECG signal. Digital filters are used to remove the power line interference and baseline wander present in the ECG signal. K-means algorithm is used to classify QRS and non-QRS-region in the ECG signal. The performance of the algorithm is validated using dataset-3 of the CSE multi-lead measurement library. Detection rate of 98.66% is obtained. The percentage of false positive and false negative is 1.14% and 1.34% respectively. The mean and standard deviation of the errors between automatic and manual annotations is calculated to validate the delineation performance of the algorithm. The onsets and offsets of the detected QRS-complexes are found well within the tolerance limits as specified by the CSE library.     

A neuromorphological analysis of the motor area of the cerebral cortex in rat pups subjected to prenatal exposure to normal and pathological blood serum]

Morphological quantitative and qualitative analysis of the pyramidal neurones in the motor cortex of rat puppies after administration of the blood serum from human donors with central motor disorders reveals the dependence of the quality and quantity of neurones from the effect of corresponding blood sera. Pathologic blood serum decreases the number and induces degradation of dendritic organization of the pyramidal neurones. The effect of the blood sera on quantitative and qualitative properties of the pyramidal neurones in rat puppies depends on the age of donor infants with central motor disorders. Blood serum from newborn babies with motor dysfunctions significantly decreases the number of labeled pyramidal neurones and results in degradation of dendritic organization, whereas sera from 11-13-year infants only insignificantly affect these characteristics.     

Basis for the cardiac-related rhythm in muscle sympathetic nerve activity of humans

We tested the hypothesis that the cardiac-related rhythm in muscle sympathetic nerve activity (MSNA) of humans reflects entrainment of a central oscillator by pulse-synchronous baroreceptor nerve activity. Partial autospectral analysis was used to mathematically remove the portion of cardiac-related power in MSNA autospectra that was attributable to its linear relationship to the ECG. In 54 of 98 cases, > or =15% of cardiac-related power remained after partialization with the ECG; peak residual cardiac-related power was often at a frequency different than heart rate. When assessed on a cardiac-related burst-by-burst basis, there was a progressive and cyclic change in the ECG-MSNA interval (delay from R wave to peak of cardiac-related burst) on the time scale of respiration in four subjects. In these subjects, as well as in some in which the interval appeared to change randomly, there was an inverse relationship between the ECG-MSNA interval and cardiac-related burst amplitude. However, in 45% of the cases, these parameters were not related. These results support the view that the cardiac-related rhythm in MSNA reflects forcing of a nonlinear oscillator rather than periodic inhibition of unstructured, random activity.     

The late prolonged motor discharges during stimulation of the segmentary afferents in rat pups: the effect of L-DOPA

In experiments on 5-30-day rat puppies, under slight urethane narcosis, studies have been made on the late prolonged discharges in extensor muscles evoked by stimulation of contralateral tibial nerve before and after injection of DOPA. Within the first 16 days, the drug completely abolished or significantly reduced late discharges, increasing the spontaneous motor activity. Beginning from the 16th day, periods of potentiation of late discharges were observed. The data obtained are discussed in relation to the development of mechanisms of control of the activity of spinal generators which are responsible for late discharges and spontaneous motor activity.     

Dinitrosyl iron complexes with glutathione in rat myocardial tissue during regional ischemia and postischemic reperfusion

Injection of dinitrosyl iron complexes with glutathione at the onset of 40-min regional myocardial ischemia in rat was shown to exert a clear cardioprotective action by decreasing the infarct size and suppressing the cardiac rhythm disturbance. After introducing the preparation, its effective accumulation with protein thiol-containing ligands in the myocardial tissue was registered be the EPR method. It was also found that in postischemic reperfusion, the rate of decrease in the content of these complexes in the ischemic area increases, which reflects effective scavenging of short-lived reactive oxygen species by the dinitrosyl iron complexes.     

The effect of chlorpromazine on the mechanogram, electrocardiogram and membranopotential of the frog heart]

The action of chloropromazine in concentrations between 10(-6) and 10(-3) M was studied with regard to its effect on contractility, ECG, and membrane potential of the isolated frog heart. In concentrations above 10(-6) a depressive influence on the amplitude of contraction was observed; the speed of contraction was reduced. The heart rate showed negatively chronotropic changes. In the ECG there was a striking expansion of the PQ interval. The membrane potential was reduced under the effect of chloropromazine depending on the concentration used. The negative influence on mechanical and bioelectrical parameters of the myocardium is interpreted to be due to membrane-related factors. A vagus-like effect is discussed, particular importance being attached to the mechanisms of the "slow-channel" system.     

Possible role of carbonic anhydrase in rat pancreatic islets: enzymatic, secretory, metabolic, ionic, and electrical aspects

The presence of carbonic anhydrase (type V) was recently documented in rat and mouse pancreatic islet beta-cells by immunostaining and Western blotting. In the present study, the activity of carbonic anhydrase was measured in rat islet homogenates and shown to be about four times lower than in rat parotid cells. The pattern for the inhibitory action of acetazolamide on carbonic anhydrase activity also differed in islet and parotid cell homogenates, suggesting the presence of different isoenzymes. NaN3 inhibited carbonic anhydrase activity in islet homogenates and both D-[U-14C]glucose oxidation and glucose-stimulated insulin secretion. Acetazolamide (0.3-10.0 mM) also decreased glucose-induced insulin output but failed to affect adversely D-[U-14C]glucose oxidation, although it inhibited the conversion of D-[5-3H]glucose to [3H]OH and that of D-[U-14C]glucose to acidic metabolites. Hydrochlorothiazide (3.0-10.0 mM), which also caused a concentration-related inhibition of the secretory response, like acetazolamide (5.0-10.0 mM), decreased H(14)CO3- production from D-[U-14C]glucose (16.7 mM). Acetazolamide (5.0 mM) did not affect the activity of volume-sensitive anion channels in beta-cells but lowered intracellular pH and adversely affected both the bioelectrical response to d-glucose and its effect on the cytosolic concentration of Ca2+ in these cells. The lowering of cellular pH by acetazolamide, which could well be due to inhibition of carbonic anhydrase, might in turn account for inhibition of glycolysis. The perturbation of stimulus-secretion coupling in the beta-cells exposed to acetazolamide may thus involve impaired circulation in the pyruvate-malate shuttle, altered mitochondrial Ca2+ accumulation, and perturbation of Cl- fluxes, resulting in both decreased bioelectrical activity and insulin release.     

The dynamics of the evoked bioelectrical activity of the brain in unconscious states

In 93 patients with mental disorders evoked bioelectrical activity of brain was studied in states of changed consciousness. Methods of evoked potentials and conditioned negative wave were applied. The obtained data allow to consider that in parameters and dynamics of bioelectrical activity changes of consciousness sphere are reflected.     

基于表面肌电信号的人体动作识别算法研究进展

表面肌电信号(Surface Electromyography,sEMG)是通过相应肌群表面的传感器记录下来的一维时间序列非平稳生物电信号,不但反映了神经肌肉系统活动,对于反映相应动作肢体活动信息同样重要。而模式识别是肌电应用领域的基础和关键。为了在应用基于表面肌电信号模式识别中选取合适算法,本文拟对基于表面肌电信号的人体动作识别算法进行回顾分析,主要包括模糊模式识别算法、线性判别分析算法、人工神经网络算法和支持向量机算法。模糊模式识别能自适应提取模糊规则,对初始化规则不敏感,适合处理s EMG这样具有严格不重复的生物电信号;线性判别分析对数据进行降维,计算简单,但不适合大数据;人工神经网络可以同时描述训练样本输入输出的线性关系和非线性映射关系,可以解决复杂的分类问题,学习能力强;支持向量机处理小样本、非线性的高维数据优势明显,计算速度快。比较各方法的优缺点,为今后处理此类问题模式识别算法选取提供了参考和依据。     

Effects of tranquilizing agents on bioelectrical activity of the rat brain]

The action of diazepam, meprobamate, trioxazine and mexidol on bioelectrical activity of sensorimotor cortex and dorsal hippocamp of the left and right hemisphere of the brain in conscious rat in free behavior has been studied. All the drugs produced a decline in the frequency of the dominant peak of EEG power spectra. Diazepam and meprobamate increased beta-activity. It is concluded that the decreased frequency may be due to an anxiolytic effect of the tranquilizers, whereas high beta-activity is related to muscle relaxant effect of some drugs.     

Various characteristics of the activity of skeletal muscles in humans and dogs during postnatal ontogenesis

At normal ambient temperatures, in absence of stress, in babies during first months of life (in contrast to less maturely born mammals), the respiratory activity of skeletal muscles is not realized, being observed only under stress conditions. In 1-1 1/2 months old puppies, after deafferentation of the hindlimb, the frequency of movements of a jerk type increases approximating the level observed in newborn animals. At normal ambient temperatures, these puppies exhibit respiratory activity of skeletal muscles which is not observed at this age in control animals.     

Functional Role of Cerebellar Purkinje Cells in Ontogenesis of Postural-Motor Reactions in Mature- and Immature-Born Mammals

In experiments on guinea pigs, cats, and rats of different ages, from newborns to adults, the postural and stato-kinetic reflexes were studied with subsequent recording of electrical activity of identified cerebellar Purkinje cells (PC) in the same animals. Simultaneously in same age group of the animals, a morphometrical study of the shape and size of Purkinje cells and their nuclei was carried out. The first signs of manifestation of reflexes of standing and of the support reaction were observed in mature-born guinea pigs as early as at the first day after birth. At this time the PC fire has an irregular and low-frequency character with long inhibitory pauses and a great dispersion of the frequency-time characteristics. In the course of postnatal ontogenesis the parameter of the ratio of frequencies of simple and complex spikes increased in all the studied animals, guinea pigs, rat puppies, and kittens, but to different degrees. The complete maturation of the PC activity in the mature-born guinea pigs took 3–4 weeks after birth, whereas in the immature-born rat puppies and kittens this process took, on average, 5–6 and 8–9 weeks, respectively. By this time, all the studied postural-motor reactions were formed. The comparison of the course of formation of the frequency-time characteristics of the Purkinje cell activity in mature- (guinea pigs) and immature-born (rats and cats) animals allowed establishing that the highest rate of maturation of the Purkinje cell activity in the mature-born animals is observed during the first half, whereas in immature-born animals, during the second half of postnatal ontogenesis. A similar rate of changes also took place at maturation of postural-motor reflexes. The complete functional maturity of the Purkinje cell occurred, as a rule, at the time period when the shape and size of the Purkinje cell body became close to the definitive ones, and their vertical and horizontal diameters reached the values characteristic of adult animals.     

The Predictive Value of Early Behavioural Assessments in Pet Dogs – A Longitudinal Study from Neonates to Adults

Studies on behavioural development in domestic dogs are of relevance for matching puppies with the right families, identifying predispositions for behavioural problems at an early stage, and predicting suitability for service dog work, police or military service. The literature is, however, inconsistent regarding the predictive value of tests performed during the socialisation period. Additionally, some practitioners use tests with neonates to complement later assessments for selecting puppies as working dogs, but these have not been validated. We here present longitudinal data on a cohort of Border collies, followed up from neonate age until adulthood. A neonate test was conducted with 99 Border collie puppies aged 2–10 days to assess activity, vocalisations when isolated and sucking force. At the age of 40–50 days, 134 puppies (including 93 tested as neonates) were tested in a puppy test at their breeders'' homes. All dogs were adopted as pet dogs and 50 of them participated in a behavioural test at the age of 1.5 to 2 years with their owners. Linear mixed models found little correspondence between individuals'' behaviour in the neonate, puppy and adult test. Exploratory activity was the only behaviour that was significantly correlated between the puppy and the adult test. We conclude that the predictive validity of early tests for predicting specific behavioural traits in adult pet dogs is limited.     

The electrocardiogram of Sepia officinalis L. (cephalopoda: coleoida) and its modulation by neuropeptides of the FMRFamide group

1. Electrocardiogram (ECG) was recorded of the systemic heart of Sepia officinalis L. from both isolated auricle-ventricle preparations.2. The peptides FMRFamide and FLRFamide evoked a concentration-dependent increase of the bioelectrical signals of the auricle (“P”-wave) and ventricle (“R”-spike) as well as a positive dromotropic effect, i.e. a shortening of the AV-interval.     

Effects of early gentling and early environment on emotional development of puppies

In recent years much interest has been focused on early experiences and numerous studies have been carried out in order to understand their effects on the behaviour of adult animals. The aim of this preliminary study was to assess the effects of early gentling and early environment on the emotional stability of puppies. Forty-three dogs (16 females and 27 males) from seven litters were used. Four of these litters (in total 23 puppies) were raised in a professional breeding kennel, while the remaining litters lived in their owner's home, in a family atmosphere. Half of every litter was gently handled daily from the 3rd day postpartum until the 21st. In order to assess the puppies’ emotionality, an isolation test followed by an arena test were conducted on every puppy at the age of 8 weeks. Video recording of the tests allowed the measurement of each puppy's vocalization and exploratory activity. Data were analysed with the Newmann–Keuls’ test comparing four groups: non-handled puppies raised in family (NHF); handled puppies raised in family (HF); non-handled puppies raised in a professional breeding kennel (NHB); handled puppies raised in a professional breeding kennel (HB).

The results suggest that early environment strongly influences the emotional stability of puppies when put in isolation: latency to the first yelp was longer (p < 0.05) in the HB group (89.46 ± 66.42) compared to NHB (45.90 ± 52.76), NHF (13.10 ± 12.17) and HF (17.90 ± 14.32), and in the NHB compared to NHF and HF; duration of vocalizations was shorter (p < 0.05) in the HB (36.77 ± 54.16) and NHB group (72.80 ± 60.57) compared to NHF (149.78 ± 19.52) and HF (132.50 ± 45.24). Moreover, early gentling had a cumulative positive effect on the emotional development of puppies. For both environments, handled puppies were calmer. In fact, they showed longer latency to vocalize and handled puppies (HB = 119.00 ± 39.85; HF = 97.12 ± 33.56) spent significantly more time (seconds) in exploratory activity (p < 0.05) compared to the corresponding non-handled puppies (NHB = 64.90 ± 34.06; NHF = 57.00 ± 26.61).

Therefore, it is concluded that the deliberate inclusion of gentling during early puppyhood would be advantageous to the emotional development and welfare of the puppy, in particular for those at risk of limited or poor tactile stimulation in the early weeks.