[The behavior of male Danio rerio after exposure of fish embryos to a simulated geomagnetic storm].

Embryos of the zebrafish, Danio rerio, were exposed to a simulated geomagnetic storm during 24 hours. Fish, developed from these embryos, left a start chamber to an aquarium more readily in comparison to those reared in a normal geomagnetic field. On the other hand, general locomotor activity in fish was not essentially different between the two groups. We hypothesize that an exposure to a geomagnetic storm during embryonic period results in enhanced tolerance to stress caused by a novel environment. A low level stress is in turn a subject to further exploration.

[Magnetic fields and fish behavior].

In the review, contemporary data on the influence of natural and artificial magnetic fields on fish behavior are considered. In this regard, elasmobranchs and teleosts appear to be studied most exhaustively. Elasmobranchs and some teleosts are able to perceive magnetic fields via electroreceptors. A number of teleosts can sense magnetic fields via sensory cells containing crystals of biogenic magnetite. Laboratory experiments and field observations indicate the influence of magnetic fields on fish locomotor activity and spatial distribution. The geomagnetic field can be used by fish for navigation. Besides, artificial magnetic fields and natural fluctuations of the geomagnetic field can affect fish embryos leading to alterations in their development. It is suggested that, afterwards, these alterations can have an effect on fish behavior.

[The increase of variability in animal behavior due to autocorrelations].

We consider a simple kind of variability in animal instinctive behavior. It is comprised of switching between alternative actions. It consists also of variations in intensity of consecutive actions. This variability is not related to ambient stimuli or needs of organism--it is spontaneous and generated by nervous system itself. At the same time, the variability is not completely random. For example, autocorrelations are observed in variations of animal's consecutive actions. An interaction of autocorrelations with random influences results in an increase of behavioral variability. The increased variability is a property of mechanism controlling instinctive behavior. This does mean that an instinctive behavior is not entirely preprogrammed. One could assert that the instinct is a mechanism for generation of behavioral variations that are not preprogrammed.

[Variability in invertebrate behavior and the problem of free will].

Behavior in animals, including invertebrates, varies spontaneously. The spontaneous variability results from nonlinear stochastic processes in nervous system. Some researchers believe this stochastic variability to be a basis for free will. Their arguments are as follows. The stochastic variability simultaneously generates different variants of behavior. As a result, animals have an opportunity to choose from possible behaviors. This ability to choose voluntarily is a core of free will. Manifestations of free will in invertebrates and humans differ quantitatively only. We dispute this viewpoint. Stochastic processes do not generate different variants of behavior simultaneously. Therefore, stochasticity does not provide animals with a real choice. This does mean that there is no proof for free will in invertebrates.

[Comparison of two kinds of functional asymmetry in the roach Rutilus rutilus (teleostei: cyprinidae)].

In the higher vertebrates, asymmetries of different functions of individual are poorly connected with each other. At present it is unknown whether this poor link is a secondary phenomenon or it is characteristic of different kinds of functional asymmetry already at early stages of vertebrate evolution. In connection with this problem, in the roach Rutilus rutilus we studied asymmetry of two behavioral reactions--movements in an annular corridor and of the C-shaped body bending at a sudden action of electrical stimulus. Different individuals prefer a certain direction of movement in the corridor (to the right or to the left). Comparison of these two kinds of asymmetry in the same individuals has shown the absence of significant association between asymmetries of different reactions. The obtained data indicate that already in the lower vertebrates, different kinds of functional asymmetry are controlled by different mechanisms and are poorly associated with each other.

[Lipid peroxidation and cytochrome P-450-dependent metabolism of xenobiotics in patients with coronary heart disease and multiple organ failure].

The aim of the investigation was to study oxidative stress and hepatic monooxygenase function (HMF) in coronary heart disease (CHD) patients with multiple organ dysfunction (MOD) after myocardial revascularization. Twenty-seven CHD patients with signs of MOD and 38 patients with an uncomplicated postoperative period were examined. The intensity of MOD was rated by the SOFA scale; oxidative stress was estimated from the values of malondialdehyde, conjugate trienes, ceruplasmin, and catalase, and HMF was evaluated from antipyrine pharmacokinetic data. On postoperative day 1, the study group showed significant signs of MOD, as well as activated lipid peroxidation (LPO) and a 1.5-fold reduction in HMF. The control group displayed an insignificant HMF suppression under less marked oxidative stress. On days 3-4 after surgery, the total MOD index was noticeably lowered. Both groups exhibited a high LPO rate and enhanced HMF. On days 10-12 postoperatively, the severity of MOD corresponded to the previous period. There was a decrease in LPO activity in both groups. HMF was found to substantially reduce in the study group and to be in line with the baseline values in the control one. Correlation analysis revealed direct and inverse relationships of the indices of MOD with LPO rates and HMF. Therefore, MOD in patients with CHD is attended by increased oxidative stress and leads to a more significant HMF reduction as compared with those with an uncomplicated postoperative period. At the same time, LPO activation is one of the cardinal causes of HMF suppression. Reduced HMF may enhance the sensitivity of CHD patients to drug therapy.

Oxidative stress and monooxygenase liver function in patients with coronary heart disease and multiple organ dysfunction syndrome.

BACKGROUND AND OBJECTIVE: The purpose of the study was to evaluate oxidative stress and liver monooxygenase function in patients with coronary heart disease and multiple organ dysfunction syndrome. METHODS: Twenty-seven patients with multiple organ dysfunction and 38 patients with an uneventful postoperative period were studied. Oxidative stress was quantified with malon dialdehyde, coupled trienes, hepatocuprein and catalase activity. Liver monooxygenase function was evaluated with antipyrine pharmacokinetics data. RESULTS: On the first postoperative day patients with multiple organ dysfunction were characterized by high lipid peroxidation (conjugated trienes: +84.7%) and significant decrease in liver monooxygenase function (clearance of antipyrine: -38%), whereas control patients had a mild oxidative stress and a slight depression in liver monooxygenase function. On the third to fourth postoperative day in both groups a considerable intensity of lipid peroxidation and increase in liver metabolism was seen. The major difference was observed on postoperative days 10-12. In both groups oxidative stress intensity decreased (conjugated trienes: +34.7%; +12.9%). In the main group liver monooxygenase function was markedly depressed (clearance of antipyrine: -35.6%), whereas in the control group liver metabolism did not deviate from the baseline. The correlation analysis showed a negative relationship between liver monooxygenase function and oxidative stress parameters. CONCLUSION: Patients with multiple organ dysfunction have considerably more oxidative stress and greater decrease in liver monooxygenase function (one and a half times) than those with an uneventful postoperative period. Lipid peroxidation is one of the main causes of depression of liver monooxygenase function. Slowdown of liver metabolism might change the pharmacokinetic response in patients with coronary heart disease.

[Habituation of caddies Chaetopteryx villosa larvae to vibrational stimulus and effect of piracetam on it].

Habituation to a vibrational stimulus was studied in intact caddies Chaetopteryx villosa Fabr. of the last age before pupation and of the larvae placed for 72 h into pyracetam solution (100 mg/l). The vibrational stimulus was shown to produce a passive-defensive reaction: the caddies were pulled into the house and stood still. In the course of the experiment the time of stay in the house decreased statistically significantly in both groups. Pyracetam did not affect the defensive reaction at the initial moment of the first vibrational stimulus, so both in the experimental and in the control groups the number of contracted larvae was equal and all of them remained in the house for the first seconds of vibration. However, the compound increased the number of larvae that did not respond to the next vibrational stimulus and decreased the number of larvae that remain in the house throughout all 10 s of action by accelerating on the whole the habituation. Hence, on this model, the mnemotropic effect of the standard nootrope has been realized, which earlier was established by other methods in mammals, the lower vertebrates, and the higher invertebrates. This indicates that this model also is perspective for comparative studies of effect of nootropic substances on the higher nervous activity.

[Laterality of the initial stage of escape response in roach (Rutilus rutilus) upon impact of alternating electric current].

The initial stage of the escape response (C-bend of the body) upon sudden impact of electric current on free-swimming fish was studied in young roach (Rutilus rutilus). More than half of the fish showed distinct behavioral laterality. i.e., a stabile tendency to bend either to the left or to the right, and retained it until the next test conducted 10 days later. The majority of fish bent to the left, but the difference between the proportions of individuals that showed opposite lateralities lacked statistical significance. This response and the type of laterality are stable and simple to record, which makes the C-bend a convenient experimental model for studying behavioral asymmetry in fishes.

[Oxidative stress and hepatic monooxygenase function in patients with coronary heart disease before and after cardiac surgery].

The parameters of lipid peroxidation (LPO) and hepatic monooxygenase function (HMF) were studied in 92 patients with coronary heart disease (CHD). After termination of and within the first 24 hours after myocardial revascularization, the levels of malonic dialdehyde and conjugate trienes were found to show 45.6 and 62.1% increases, respectively. The half-life of antipyrine (AP T(1/2)) increased by 23.5%. Studies on postoperative days 3-4 and 10-12 revealed a reduction in LPO rates and normalized HMF. After off-pump surgery, LPO and HMF significantly unchanged. On the contrary, open heart surgery resulted in a noticeable activation of LPO and an almost 1.5-fold decrease in HMF. The increase in oxidative stress and the deceleration of hepatic microsomal oxidation were ascertained to be directly related to the duration of extracorporeal circulation and the time of myocardial ischemia. After surgery, the rate of LPO and the reduction of HMF were more considerable in patients with multiple organ dysfunctions, as compared with the uncomplicated postoperative period. Within the first 24 hours following surgery, AP T(1/2) increased by 83.4%, but on postoperative days 10 to 14, it remained to be decreased by almost 1.5 times as compared with the baseline. Thus, LPO activation is one of the leading mechanisms of decelerated hepatic xenobiotic biotransformation after myocardial revascularization. Diminished lower HMF enhances the sensitivity of CHD patients to drug therapy and requires a differential approach to its use.

[The conflict between optimisation and orderliness in building behaviour of the caddis fly, Chaetopteryx villosa Fabr.(Limnephilidae: Trichoptera), larvae]. / Protivorechie mezhdu optimizatsiei i uporiadochennost'iu v stroitel'nom povedenii lichinok rucheinikov Chaetopteryx villosa Fabr. (Limnephilidae: Trichoptera).

The Optimal Foraging Theory predict that an animal should restrict its searching activity to those patches of environment, where the ratio of gain to time and energy spent is maximal. Experimenters usually verify the prediction against the null hypothesis of random activity distribution between patches. As animals always prefer profitable patches to some degree, experimental results can always be interpreted as confirmation of the theory. In opposite to this approach, we put forward the "regularity hypothesis". According to this hypothesis, the finding of a profitable item in some patch makes an animal to stay and test more items within the patch. The readiness to test decreases if the profitability of these items is low, and the animal eventually leaves the patch. It also searches in other patches less carefully. As a result, positive and negative responses to items are repeated by ordered series. In general, this regularity of responses helps animals to choose profitable patches. However, animals may also ignore some profitable patches because of the regularity, so that the behavioural optimazation fails. The regularity hypothesis have been tested in experiment with the search of building material and patch choice by caddisfly larvae. The first of two experimental patches contained egg shell fragments (profitable building material) mixed with a sand (unprofitable). The second patch contained sand only. Larva stayed within the first patch after a shell had been found, so that the probability to find more shells increased. However, larvae started walking after they had found several sand particles. Once starting to walk, they found new shell fragments and tested them, but tended to reject them and eventually leave the patch. Moreover, upon returning to the first patch, larvae also might reject fragments and leave the patch again. Rejections are accounted for by the fact that the duration of testing was too short to identify fragments correctly. As a result, negative responses were repeated to a certain degree independently of the profitability of building material, and the patch choice was not optimal. These results are agreed with the regularity hypothesis. It is argued that the hypothesis can be used as an alternative to the Optimal Foraging Theory.

[The variability of the reaction to a visual stimulus in goldfish, Carassius auratus L. (Cyprinidae: Pisces)]. / Izmenchivost' reaktsii na zritel'nyi razdrazhitel' u zolotykh rybok Carassius auratus L. (Cyprinidae: Pisces).

Animal's responses to repeated identical stimulation are notoriously variable. The variability is not always resulted from differences between individuals, stimulus action, or habituation. Goldfish's responses to a visual stimulus were studied in order to reveal the nature of variability. The experimental device consisted of a white circular corridor, and the black band stimulus drown across the corridor. Fish responded to the stimulation by an increase in frequency of turns in the vicinity of the band. The response, however, was not always positive: sometimes fish passed by the band with no turns (negative response). The significant tendency to repeat positive and negative responses by series was observed. Intensity of the response differed between individuals, and some individuals never responded at all. The simulating dynamic model of goldfish behaviour was studied both qualitatively and quantitatively. The model assumes that the control mechanism of the behaviour is influenced by the noise (fluctuations of nervous activity) which causes phase transitions in the mechanism. The similarity of the model's behaviour to experimental data suggests that the response variability observed in goldfish resulted from the self-organising process. Therefore, the variability should persist even in the absence of any variations in an external stimulation, as well as in the absence of individual differences.

[Cerebral, central and intracardiac hemodynamics in patients with progressive arterial hypertension following the surgical suppression of adrenal hyperfunction]. / Sostoianie tserebral'noi, tsentral'noi i vnutriserdechnoi gemodinamiki u bol'nykh progressiruiushchei arterial'noi gipertenziei posle khirurgicheskogo podavleniia giperfunktsii nadpochechnikov.

Forty-eight patients with progressive (malignant) arterial hypertension resistant to conservative therapy were subjected to surgical portalization of the adrenal blood stream in order to metabolize excessively produced aldosterone in the liver of the patients. Cerebral hemodynamics was studied before by tetra- and bipolar rheoencephalography, central hemodynamics was studied by tetrapolar transthoracic rheography, and intracardiac hemodynamics by echocardiography before and after surgery; blood plasma aldosterone and hydrocortisone concentrations and plasma renin activity were measured. A significant reduction of arterial pressure, elimination or alleviation of subjective and objective manifestations of chronic hypertensive encephalopathy were seen in the majority of patients after surgery. Cerebral blood flow improved, blood plasma aldosterone and renin activity reduced, myocardial hypertrophy decreased, and a trend to normalization of intracardiac hemodynamics was observed.

[The indications for the suppression of adrenal hyperfunction in a progressive course of hypertension]. / Pokazaniia k podavleniiu giperfunktsii nadpochechnikov pri progressiruiushchem techenii gipertonicheskoi bolezni.

The authors analyze the results of the surgical treatment of patients with progressive essential hypertension (PEN). The treatment involved cryodestruction (adrenalectomy) of the right adrenal and autotransplantation of the left adrenal on the vascular peduncle into the transverse mesentery. Before the operation the data on water-salt homeostasis, central and cerebral hemodynamics and on the renin-angiotensin-aldosterone system attested to PEH. 1 to 3 years after the operation natriuresis was revealed (210% of the initial value), as were a decrease of the total peripheral vascular resistance, amelioration of the cerebral blood flow and peripheral blood aldosterone lowering from 246 +/- 17 to 90 +/- 14 sh/ml.

[Differential diagnosis of jaundice based on antipyrine metabolism]. / Differentsial'naia diagnostika zheltukh po metabolizmu antipirina.

The investigation of detoxicating function of the liver in 85 patients has shown that the indices of antipyrine clearance in patients with one-month-long parenchymatous jaundice and obstructive cholestasis were reliably different. However, longer terms of mechanical jaundice with concomitant pronounced cholangiohepatitis made the liver metabolism progressively worse. The authors recommend using antipyrine tests in differential diagnostics of parenchymatous and mechanical jaundice.