Changes in the acetylcholine--cholinesterase system in the dynamics of experimental boltulin poisoning]

A study was made of the effect of botulin, type B, on the acetylcholine-cholinesterase system. High doses of the toxin increased the level of acetylcholine in the peripheral blood nervous system, as well as in the central nervous system. Injection of DLM of the toxin results in elevation of the acetylcholine level in the peripheral nervous system. Cholinesterase activity was practically unchanged.     

山羊卵母细胞的减数分裂进程

The meiotic progression of goat oocytes from follicles of different diameters was investigated in this study. The results were summarized as follows: (1) The in vitro meiotic maturation capacity was different among oocytes from follicles of different diameters. And thus oocytes from < or = 0.5 mm follicles were unable to resume meiosis; oocytes from 0.8-1.2 mm follicles were capable to resume meiosis, but could develop only to MI stage (60% at 24 h); oocytes from 1.5-5 mm follicles had acquired full-meiotic maturation capacity and 91% of them developed to M II stage at 24 h of culture. (2) The percentage of oocytes with intact-germinal vesicles from 1.5-5 mm follicles decreased significantly during 2-8 h of in vitro maturation and the decrease was even more rapid during 4-6 h of culture (from 60% to 19%, p < 0.0005). The percentage of oocytes at M I-stage increased from 24% to 61% during 6-12 h of in vitro maturation, and it then decreased. By 24 h of culture, only 2% oocytes remained at M I-stage. Twenty one percent of the oocytes in this group developed to M II-stage at 16 h of culture, and by 24 h of culture, 91% were at M II-stage. (3) Statistic analysis of the meiotic progression (the duration of each cell cycle stage) of oocytes from 1.5-5 mm follicles showed that GV stage lasted from 0 to 3 h of culture, prometaphase-I stage was from 3.0 to 7.0 h, metaphase-I stage was from 7.0 to 14.6 h, anaphase-I/telophase-I was from 14.6 to 18.4 h and metaphase-II stage lasted from 18.4 to 24 h. (4) Whether the oocytes capable of GVBD and entrance of M I developed to M II, the timing of meiotic progression prior to M I was similar. In summary, our results provided necessary data for studies on the mechanisms and control of meiosis in mammalian oocytes.     

Changes in the immune status parameters and their correction in various forms of tick-borne encephalitis]

Comparative investigation of immune status indices in patients with fever form of vernal encephalitis (group 1), with inapparent form with prolonged antigenemia (group III) and with short-term antigenemia (group II) was performed for the first time. Total 99 patients were under investigation. It was shown that in group I selective damage of immune system at T-level took place. In patients of group III immune system at all levels was less involved and humoral factor were changes. In patients in group II no significant change in immune system were registered. Activity of different immune correctors (thimalin, 4-iodoantipirine, leukinferon) was investigated in vitro. This preparations had stimulating effect in blood samples of patients with decreased immune status. In the patients with unchanged immune status no effect was demonstrated. The most prominent effect was revealed in the case of 4-iodoantipirine--interferon inducer.     

Changes in the configuration of conditioned reactions of visual cortex neurons during changes in reinforcement parameters]

In order to study the influences of controlled changes of defensive integration on the activity of visual cortical units their responses to a conditioned light flash and electric cutaneous stimulation with a 600 msec interval between them were recorded in experiments on alert rabbits. It has been shown that in a third of the neurones the types of reaction to light flashes and electric stimuli coincide. The changes in parameters of the reinforcing shock led to a changed response of most cells to the conditioned photic stimulus and electric stimulation. The changes may have affected units which produce any activation phase, including cells with activity characteristic of detectory (simple and complex) visual neurones. The data obtained suggest that the special function of the visual cortex is used in different ways in systemic mechanisms of conditioned and unconditioned defensive acts and that the integrated system of a behavioral act exerts control both on the use of the unit in a certain systemic process and on its receptive field.     

Changes in cerebral near infrared spectroscopy parameters during manual acupuncture needle stimulation]

Near-infrared spectroscopy (NIRO 300, Hamamatsu Photonics, Japan) was used to monitor human cerebral function in the central region during manual acupuncture needle stimulation of the large intestine 4 (LI.4) point in 16 adult volunteers (9 females, 7 males; mean age 23.9 +/- 6.0 (SD) years, range 19-45 years). We found a significant (p < 0.001) decrease in oxyhaemoglobin after needle insertion and stimulation (duration 20 sec.), accompanied by an increase (p = 0.003) in deoxyhaemoglobin. A repeat stimulation showed similar effects. Cytochrome oxidase aa3 remained unchanged during stimulation. The results demonstrate that near-infrared spectroscopy may be a noninvasive method of measuring regional changes in cerebral haemodynamics resulting from peripheral acupuncture stimulation.     

Changes of gas exchange parameters and of functional-biochemical properties of erythrocytes in dynamics of experimental anemia in rats

In experiments on male Wistar rats, in a specially constructed computerized installation, O₂ consumption by the animals in comparison with changes of hematological, biochemical, and rheological blood properties is studied after anemization—acute blood loss (12–15% of the total blood mass). An increase of the O₂ consumption by the organism and tissues by 18–28% has been revealed for the first 7 days after the blood loss, in spite of a pronounced decrease of hematocrit and of the amount of erythrocytes and hemoglobin in peripheral blood by 20–25% of the initial level. There was a 5–10-fold increase of the content of immature erythrocyte forms—reticulocytes and a progressive rise of cell acidic resistance, which is characteristic of young erythrocyte forms. An increase of O₂ consumption at a decrease of the blood oxygen capacity (a low hemoglobin level) seems to be due to the more efficient transport and yield of O₂ to tissues. At the 3rd and 7th day after the blood loss, activity of Na,K-ATPase has been found to increase by 60% and 20%, respectively. Analysis of the erythrocyte rheological properties has shown that the maximal firmness of aggregates (U_q) and the aggregation rate (1/T) decrease progressively beginning from 3 days after the blood loss; index of deformability (I_max) turned out to be elevated by 7–11%, probably due to an increase of the cell membrane elasticity. The conclusion is made that changes of erythrocyte rheological properties are interconnected with changes of the Na,K-ATPase activity and are directed at optimization of blood circulation in large vessels and the capillary network.     

Changes of certain parameters of renal function in patients with allogenic bone marrow transplantation]

Serum creatinine and urea changes as well as protein, erythrocytes, and leucocytes excretion with the urine in allogenic bone marrow recipients are discussed. An increase in serum creatinine and urea together with proteinuria and hematuria were noted in 1/3 of patients treated with busulphan and cyclophosphamide prior to bone marrow transplantation. In cases of bone marrow graft rejection or post-transplantation complications no abnormalities in the value of investigated parameters were noted, especially immediately before death. Possible causes of such renal function disorders are also discussed.     

The dynamics of the amplitude-time parameters of the seismocardiograms of students with different levels of physical fitness]

The reliable scientific data on the physiological mechanisms of the heart activity regulation have been obtained using a seismocardiographic method. Analyzing physical and mental loads of students in different periods of the academic year, it has been revealed that an increase in the amplitude of the first seismocardiographic complex and the development of the amplitude coefficient occur after the maximum cycle-ergometric loading, that is a good response of the contractile myocardium to loading. During the winter term, at rest an increase in the amplitude of the first seismocardiographic complex and a decrease in the amplitude of the second one are observed in most of the students, that is, probably, connected with the emotional and intellectual factors of the session period. The optimal value of energy coefficient per second is set up (it is 1.5 val.). It reflects a relationship between the energy processes during heart systole and diastole.     

Early influences on the tempo of puberty

Fetal growth retardation appears to be associated with an increased risk of premature adrenarche, early puberty, polycystic ovary syndrome and associated fertility problems. In a rat model of intrauterine growth retardation, based on ligation of the uterine arteries, the onset of puberty was delayed in female pups, with anovulation during the first cycle. The ovaries showed a lower number of follicles. The onset of puberty was also delayed in male pups. Testosterone production was lower in these growth-retarded rats compared with controls. The relationship between birth weight and the onset of puberty and pubertal progression in different cohorts of healthy children has been examined. In girls, no differences were observed in timing and progression of puberty, including age of menarche, between groups of different birth weights. In boys, a relatively delayed onset of puberty was observed in those with low birth weight, with a normally timed progression. In children with low birth weight, particularly boys, higher dehydroepiandrosterone levels were found compared with children with a normal birth weight, indicating an overactive adrenal gland in children with low birth weight. These data indicate that impaired fetal growth may have long-lasting effects on pubertal development. The fact that results of human studies on the relationship between fetal growth and the onset of puberty are often controversial may be explained by the heterogeneity of children born small for gestational age with respect to the intrauterine insult that they experience. From rat studies, it is clear that a serious intrauterine insult associated with growth failure can lead to dysregulation of puberty and gonadal function.     

How group size affects vigilance dynamics and time allocation patterns: the key role of imitation and tempo

In the context of social foraging, predator detection has been the subject of numerous studies, which acknowledge the adaptive response of the individual to the trade-off between feeding and vigilance. Typically, animals gain energy by increasing their feeding time and decreasing their vigilance effort with increasing group size, without increasing their risk of predation ('group size effect'). Research on the biological utility of vigilance has prevailed over considerations of the mechanistic rules that link individual decisions to group behavior. With sheep as a model species, we identified how the behaviors of conspecifics affect the individual decisions to switch activity. We highlight a simple mechanism whereby the group size effect on collective vigilance dynamics is shaped by two key features: the magnitude of social amplification and intrinsic differences between foraging and scanning bout durations. Our results highlight a positive correlation between the duration of scanning and foraging bouts at the level of the group. This finding reveals the existence of groups with high and low rates of transition between activities, suggesting individual variations in the transition rate, or 'tempo'. We present a mathematical model based on behavioral rules derived from experiments. Our theoretical predictions show that the system is robust in respect to variations in the propensity to imitate scanning and foraging, yet flexible in respect to differences in the duration of activity bouts. The model shows how individual decisions contribute to collective behavior patterns and how the group, in turn, facilitates individual-level adaptive responses.     

The dynamics of the activity parameters of the neuronal populations in the dorsal hyperstriatum of hens depending on the afferent input in ontogeny]

Studies have been made on the properties of neuronal populations of the dorsal hyperstriatum of the forebrain in hens beginning from the 18th day incubation up to the 7th day after hatching, which were incubated and kept either in darkness or under periodic illumination. Among the investigated parameters of multicellular activity, mean frequency of the discharge activity was found to be most susceptible to the level of external light afferentation in ontogenesis. The discharge activity was more intense in the left hemisphere of chick embryos and chicks from illuminated group, which may be associated with asymmetrical visual afferentation resulting from embryonic position within the egg, and its modulating effect on synchronization processes in the adjacent neurones of the given structure.     

Changes in cardiorhythm and its stochastic parameters in first-graders with normal neuropsychological development and in children with speech disorders during performance of intellectual activity

Influence of positive and negative motivation on the performance efficiency and some stochastic characteristics of RR-interval fluctuations in speech association experiment was studied in two groups of pupils of the first class: normally developing children and children with speech deviations. It was shown that children with normal development achieve their maximal productivity mostly under the influence of their inner motivation without external stimulation, while for achieving the maximal productivity by children with speech deviations the positive external motivation is required. Baseline ECG recordings in two groups of children significantly differed only in the standard error of the RR-intervals that was decreased in the deviant children. Under conditions of positive motivation, the maximal intellectual productivity in both groups of children was achieved at significantly different values of the fractal index beta. The findings are discussed in terms of the influence of motivation on the verbal performance and concomitant adaptation.     

Cineradiography of monkey lip-smacking reveals putative precursors of speech dynamics

A key feature of speech is its stereotypical 5 Hz rhythm. One theory posits that this rhythm evolved through the modification of rhythmic facial movements in ancestral primates. If the hypothesis has any validity, then a comparative approach may shed some light. We tested this idea by using cineradiography (X-ray movies) to characterize and quantify the internal dynamics of the macaque monkey vocal tract during lip-smacking (a rhythmic facial expression) versus chewing. Previous human studies showed that speech movements are faster than chewing movements, and the functional coordination between vocal tract structures is different between the two behaviors. If rhythmic speech evolved through a rhythmic ancestral facial movement, then one hypothesis is that monkey lip-smacking versus chewing should also exhibit these differences. We found that the lips, tongue, and hyoid move with a speech-like 5 Hz rhythm during lip-smacking, but not during chewing. Most importantly, the functional coordination between these structures was distinct for each behavior. These data provide empirical support for the idea that the human speech rhythm evolved from the rhythmic facial expressions of ancestral primates.