Collagen synthesis by cultured skin fibroblasts from siblings with hydroxylysine-deficient collagen. It has been previously shown that dermis from subjects with hydroxylysine-deficient collagen contains approximately 5% of normal levels of hydroxylysine and sonicates of skin fibroblasts contain less than 15% of normal levels of collagen lysyl hydroxylase activity. However, cultures of dermal fibroblasts from two siblings with hydroxylysine-deficient collagen (Ehlers-Danlos Syndrome Type VI) compared to fibroblasts from normal subjects synthesize collagen containing approximately 50% of normal amounts of hydroxylysine. The lysyl hydroxylase deficient cultures synthesize both Type I and Type III collagen in the same proportion as control cultures. Both alpha 1(I) and alpha 2 chains are similarly reduced in hydroxylysine content. Collagen prolyl hydroxylation by normal collagen lysyl hydroxylation is the same with or without ascorbate supplementation. In mutant cells the rate of prolyl hydroxylation measured after release of inhibition by alpha, alpha'-dipyridyl is the same as in control cells. The rate of lysyl hydroxylation is reduced in mutant cells but only to approximately 50% of normal.


Preliminary studies on the composition and rheological properties of the extracellular polysaccharide synthesized by Pseudomonas PBI (NCIB 11264). A microorganism isolated from a carbohydrate-rich industrial effluent synthesized an exocellular slime polysaccharide composed of glucose and galactose in a molar ratio of 7.45 +/- 0.68 : 1, and two non-carbohydrate substituents acetate (3--4%) and pyruvate (5--9%). Contamination by rhamnose and mannose was detectable in crude polysaccharide samples. Solutions of the polysaccharide were pseudoplastic, but not thixotropic, and formed gels in the presence of certain trivalent cations.


The effect of oxidant stress on diamide-treated human granulocytes. The role of sulfhydryls in the protection of human polymorphonuclear neutrophils against extracellular oxidant attack was investigated by simultaneously exposing polymorphonuclear neutrophils to the thiol-oxidizing agent diamide and the oxidant-generating system xanthine-xanthine oxidase. Neither diamide nor the oxidants generated by the xanthine-xanthine oxidase system alone impaired the burst in chemiluminescence, hexose monophosphate shunt activity or formate oxidation normally seen during polymorphonuclear neutrophil phagocytosis. Incubation of the polymorphonuclear neutrophils simultaneously with diamide and xanthine-xanthine oxidase markedly impaired polymorphonuclear neutrophil phagocytosis, hexose monophosphate shunt activity, chemiluminescence and formate oxidation. Although the polymorphonuclear neutrophils exposed to diamide and xanthine-xanthine oxidase did not respond to a variety of phagocytizable stimuli, trypan blue exclusion was normal and hexose monophosphate shunt activity could be stimulated by diamide. The damaging effect of the diamide xanthine-xamthine oxidase system could be blocked by the addition of superoxide dismutase or catalase, but not by hydroxyl radical or singlet oxygen scavengers. We hypothesize that an unidentified population of thiols may play a role in protecting the polymorphonuclear neutrophil from endogenously derived oxidants.


Isolation and identification of S(+)-3-hydroxyisobutyric acid in the urine of rats loaded with isobutyric acid. 3-Hydroxyisobutyric acid has been isolated from the urine of rats loaded with sodium isobutyrate. An optical rotation measurement of the methyl ester derivative shows this compound to be the S(+) stereoisomer. This is the same stereoisomer that has been previously identified in cultures of bacteria incubated with ammonium isobutyrate (Aberhart, D.J. (1977) Bioorg. Chem. 6, 191--201).


[Several estimations of the solutions of the system of differential equations describing electron transfer processes]. Some inequalities are deduced in relation to probabilities of the states of molecules-carriers complex. The existing hierarchy for velocity constants in electron transfer chains permits the application of deduced inequalities both for the simplification of the initial equation system, and for different evaluations, as for example for determining the maximum velocity of electron transport through the complex, for determing the number of electrons in the complex etc.


[Photooxidation and photochemiluminescence of different proteins]. Information has been obtained concerning photooxidation rate of 18 proteins, blood plasma, glycyl triptophane and some amino acids under UV-irradiation. It has been shown that the majority of the objects studied have the quantum yields of oxygen absorption in the range 0.2--0.6%. Photochemoluminescence of proteins was also investigated. It has been found that protein photochemoluminescence characteristics differ significantly, their main differences are concerned with intramolecular reaction of peroxide free radicals responsible for chemoluminescence with protein acceptors.


[Two possible mechanisms for forming supramolecular structures of the collagen type]. Comparative electron microscopic investigation of submolecular structure formation of native collagen molecules and denaturated collagen peptides in tropocollagen and gelatin gels was carried out. Submolecular terminal structures were similar. Fibrils exist with cross striation region of 64--70 nm. In spite of this the intermediate steps in the formation of both structures differ. In case of collagen the bundle of parallel microfibrils forms the thick fibrils. In case of gelatin the aggregates of spherical anisotropic particles form the fibrils of gelatin gels.


[Electromechanical model of an enzyme-substrate kompleksa]. An electro-mechanical model is suggested for studying the hydrolytic reaction catalyzed by an enzyme having a domain structure. The fixation of the necessary set of reagents configurations by the enzyme molecule allows the reaction rate acceleration. The model suggests specificity of the enzyme action. The model makes more clear the phenomenon of complementarity between the unchanging part of the substrate molecule and the active site of the enzyme which require not only the spatial fit but also the agreement of some physical properties, such as atom and group partial charges. The model is selfconsistent, i. e. it is not contrary to the existing data on the structural and functional properties of enzyme proteins having the domain structure.


[Changes in the elastic properties of lipid bilayers as a result of different procedures]. The bilayer elasticity modulus approximately E perpendicular is sensitive to alternative electrical field, addition of different detergents and proteins incorporation. The detergents modify the value E1APPROXIMATELY E perpendicular] several times, the kinetics of this effect is more frequently biphasic and its shape and time parameters are characterized with a considerable dispersion; in general the [approximately E perpendicular] value increase for soft membranes and decrease for the membranes and high elasticity modulus. The proteins incorporation as well as the destruction of the membrane is accompanied with the general structure transition of the whole membrane. The measurement of the elasticity modulus is an effective test of protein incorporation in bilayers.


[Reaction between liposomes and biomolecular membranes]. Small liposomes did not change the resistance of bimolecular lipid membranes (BLM) in monovalent ion solution (less than or equal to 0.5 M). The interaction between liposomes containing cholesterol and BLM free from cholesterol in the solution of polyene antibiotic nystatine induced anion selectivity and smooth growth of BLM conductance by 4--5 orders. The addition of the liposomes containing cholesterol and nystatine induced a step-like fall of BLM resistance by 2--3 orders. Both cation-selective and anion-selective steps was observed. The effects observed point to the fusion and incorporation of liposome into BLM.


[High time resolution x-ray study of the dynamics of a single muscle contraction]. A method of the diffraction cinema which enables to study the time-course of structural changes during twitch contraction is described. The method is based on using synchrotron radiation, position-sensitive counter and small-angle focusing X-ray camera. Only 0.1 s is required to record a good muscle X-ray diagram: meridional diagram contains all layer-lines beginning with the 429 A; the equatorial diagram contains 5 reflections including very weak alpha-reflection. The method allows to record 64 sequent diffraction patterns with different duration (1--2000 ms). The experiment is handled by a computer. Some tens of the films of isometric twitch contraction with time resolution of 3--20 ms have been obtained. During isometric contraction considerable changes in the intensity of both meridional and equatorial reflections were found. The changes were interpreted as indicating movement of cross-bridges toward the thin filaments. During the latent phase there are no visible changes in the intensity of the reflections; the result indicates that during this phase there are no structural changes in position and configuration of cross-bridges.


[Functional role of the structural nonequivalence of the F-actin subunits of thin filaments]. According to the model of the actin-containing filaments suggested earlier by Frank and author thin filaments of sceletal muscle can be considered as a linear polymer chain composed of structural units each of which can adopt either of two different structural states -- I (inhibited) and A (activated). The structural unit can be represented by a block of two complementary functional units of the thin filaments. The data available indicate that the length of the A-state is slightly longer than the length of the I-state. In this case the relative amount of the functional units in A- and I-states in thin filaments must depend not only on the Ca2+ concentration in sarcomere, but also on the value of the external force pulling the thin filaments in contracting muscle. It is shown that this property of the thin filaments may provide the molecular basis of Hill-equation and the selfadaption of contractile machinery to the value of the external load on muscle.


[Effect of phalloidine on the contractile properties of glycerinized skeletal muscle]. The phalloidin addition (20--30 mkg/ml) is shown to be followed by complex transient of isometric tension of fibres in low Ca++ concentration. The process is accelerated by the temperature increase. The phalloidin treatment does not cause the loss of contractility and Ca++-sensitivity of isometric tension. The treated fibres lost their ability to work in an autooscillation mode at 20--23 degrees C but were in condition to do this at the temperatures higher than 30 degrees C. The mechanical properties of rigor fibres as well at the myosin aggregation dependence on ionic strength were not markedly changed after the treatment. The results make it possible to conclude that the autooscillation mode of contraction is due to some feedback via I-filaments. The actin modification by phalloidin disturbs this feedback.


Oocyte growth.

Oocyte growth. The main elements of reproduction are exposed with emphasis on its preparation during the larval stage. The system oocyte-nurse cells-follicular cells is described and the principal features of egg morphogenesis are indicated. Two types of problems are concentrated on : 1) sequential determination of growth and evolution of the follicle in the ovarian tube, 2) morphological and biochemical aspects of chorion formation. Variation in the functioning of the oocyte's morphogenetic system is explored with discussion of the role of larval alimentation, temperature, hormonal environment and genetic factors.


Studies on the anesthetic mechanism of carbon dioxide by using Bombyx mori larvae. The study of heartbeat variations of Bombyx mori larvae submitted to CO2 narcosis has provided new information on carbon dioxide anesthesia. Purely anoxiant action must be dismissed. Action at a nerve level is possible since CO2 produces the same effect as ether, which is a classical anesthetic.


[Luminescence emitted from the second excited electron state (S2) of chlorophyll a]. A weak emission band at 582 nm in the spectrum of chlorophyll a in ether was observed under the 568.1 nm laser excitation. By means of the excitation spectra and using the method of fluorescence detection of triplet state this band was assigned to the radiative transition S2 leads to S0 of the chlorophyll a molecule. The evaluated value for the lifetime of the excited state S2 is about 0.3 to 0.8 ns.


Hemocytes and hemocytopoiesis in Silkworms. A brief review is presented of the current state of ultrastructure, cytochemistry, and physiology of the hemocytes and meso- and metathoracic peri-imaginal-wing organs in silkworms. According to the accepted morphological classification, five circulating types of hemocytes are recognized in Bombyx mori as well as in Antheraea pernyi. They are prophemocytes or stem cells, plasmatocytes or pre-differentiated cells and three specialized cells, granulocytes, spherule cells and oenocytoids. During post-embryonic development the last four types are the most common in the circulating hemolymph. Plasmatocytes are considered to be pluripotent cells from which granulocytes, spherule cells and oenocytoids are derived. Contrary to the situation in most insects the plasmatocytes are not phagocytic in Antheraea. The granulocytes are efficient phagocytes. Both plasmatocytes and granulocytes are involved in pinocytosis. Another possible function of the granulocytes is hemolymph coagulation. The function of the spherule cells which contain a paracrystalline material (muco- or glycoproteins) is by no means clear. The phenoloxidase activity found within the cytosol of oenocytoids appears effective against the natural monophenol and diphenol substrates. The involvement of oenocytoids in the complex metabolism of phenols and particularly in the production of plasma phenolases has been reported. The mitotic division of five circulating hemocyte types is well known and was long regarded as the only mechanism of postembryonic hemocyte production. We present for silkworms, experimental evidence of the hemocytopoietic function of the meso- and metathoracic organs surrounding the imaginal wing discs. Ablation experiments demonstrate that the mitotic activity of free hemocytes is unable to maintain the normal hemocytogram in the absence of the two paris of organs. These organs are typically divided into cell islets ensheathed by a connective tissue membrane. Two types of islets may be classified by the disposition of the cells : the compact islets or aggregations of stem cells and the reticulate islets which are mainly composed of hemocytes at different steps of differentiation. The relative number of prohemocytes in the total hemocyte population ranges from 84 to 97 p. cent in organs of Antheraea pernyi. This well-defined cell type appears to be the major hemocyte type in hemocytopoietic organs. In Antheraea, the mitotic index (the relative number of mitotic hemocytes in the total cell population) varies from 0.5 to about 3 p. cent. Finally, our data direct attention to cyclic functional changes such as mitotic divisions and hemocyte differentiation which run parallel to the molting cycle.


[Use of the prompt identification principle in controlling complex motor systems (speed control)]. Some aspects of the adaptive control of animal motor system described in the form of differential equations system were discussed. It was considered that the system of motor control is a multilevel one in which each level has a definite range of correction capacity for movement deviations. Since the time of the sensory signal passing over the control nervous loop is comparable with the duration of the movement controlled, a mechanism of the fast adaptation to a nonstationary situation was suggested. This mechanism is based on the principle of urgent identification of the motor system state at the moment of movement initiation. Urgent identification occurs by means of estimating of the motor system reaction to a small precisely measured motor signal (test-impulse), which was generated simultaneously with the basic motor command outflow but reached the spinal motor structures more quickly. The mathematical description of the urgent identification principle performance in the motor control in the case of velocity estimating was suggested.


[Effect of illumination prehistory on P700 redox transition kinetics in bean leaves]. The state I in equilibrium state II transients in bean leaves were studied by ESR method at various temperatures. P700 photooxidation induced by far-red light after leaf adaptation to darkness demonstrated two phases. This kinetics correlated with two overshuts in the kinetics of P700+ reduction observed after additional switching on the light exciting Photosystem II. In the atmosphere of gaseous nitrogen P700 behaviour was reversibly modified. Multiphase character of P700 kinetics correlated with the state I in equilibrium state II phenomenon as measured by chlorophyll a fluorescence from Photosystem II. The rate-limiting step at the acceptor side of Photosystem I electron transport chain may be considered as a point controlling the state of intact chloroplasts.


Occurrence of an active regulatory mechanism of protein synthesis during starvation and refeeding in Bombyx mori fat body. The origin of the amino acids which participate in protein synthesis at the recovery from starvation have been determined in the fat body from Bombyx mori larvae. Endogeneous amino acids have been labelled with [3H] leucine and ingested ones with [14C] leucine, allowing their discrimination in the organism. 22 minutes after refeeding, proteosynthetic activity of the fat body, estimated by the polysome level, is increased 2.5 fold. Endogeneous leucine represents more than 90 p. cent of the leucine present in nascent polypeptides. Free leucine pools of the fat body and of hemolymph increase, mainly through the release of endogeneous leucine. It is therefore concluded that refeeding with amino acids induces the production of a signal or critical factor, responsible for the increase in proteosynthetic activity in the fat body.


[Nonequilibrium distribution as a feature of biological systems]. It is suggested that the amount of energy extracted by a dissipative biological system from macroergic compounds depends on the energetic state of the system. The non-linear character of this relationship with the maximum in intermediate phases and presence of the upper limit of energetic states in the system with an energy increase cause a decrease of population of intermediate levels and an increase of the upper and lower levels. The antientropic distribution is presented as a principal thermodynamic peculiarity of biological systems.


[Possible DNA conformations].

[Possible DNA conformations]. The complete analysis of possible DNA structures has been undertaken in the space of dihedral angles. The structural sets obtained join energetically and geometrically possible conformations. Thus, the necessary condtions of existence are fulfilled for these structural forms. The half of our structural families includes all structures and structural sets proposed by other authors [10, 24]. Other six families have not been presented elsewhere. The results of the energy optimization suggest the left handed forms are unfavourable energetically, because main chain torsional term and the energy of nucleotide moiety. At the same time there is a great number of various lefthanded forms.


DNA synthesis and endomitoses in the giant nuclei of the silkgland of Bombyx mori. At the first symptoms of organisation of the silkgland in the embryo, mitoses stop and nuclei start to grow. Through autoradiographic studies, performed after sequenced labeling with [3H] and [14C] thymidine, the durations of the different phases of DNA synthesis cycles (T = 42 to 48 h, S = 22 to 25 h, G = 20 to 23 h) are established. These durations are in fact identical during the second and the third instar, and the same, whatever region is concerned : posterior, middle or anterior parts. A model has been established to account for the distribution of the S phases during the second and third instars. The DNA synthesis in all nuclei of a given region has been followed during the first four instars by labelling with [3H]thymidine. The activity goes through maxima and minima, depending on the percent of nuclei synthesizing DNA and their synchronism, both being characteristic of each region; long resting periods are observed during the molting stages of the first three instars in the middle and the anterior parts. The coincidence is obvious between the maxima and minima and respectively the S and G phases of the model. DNA assays agree with the distribution of cycles established by autoradiography if one admits that each cycle does lead to a doubling of the amount of DNA. The overall DNA synthesis from the diploid value is estimated to correspond to 18-19 endomitoic cycles in the nucleic of the posterior part, 19-20 cycles of those of the middle part and 13 in those of the anterior part. The analysis of chromosome structures, by squashing the nuclear content, shows that existence of a complete endomitotic cycle: the doubling of chromosomes is associated with condensed structures, alternating with a decondensed state of chromatin, responsible for the DNA synthesis. The female heterochromatin undergoes a restricted morphological cycle delayed with respect to bulk chromatin. It is characterized by a late DNA duplication and by non dispersed daughter chromosomes. Some of these aspects are, to a lesser extent, reproduced in groups of autosomic chromosomes.


The chemical structure and the crystalline structures of Bombyx mori silk fibroin. Some recent data (i.e. published in the last ten years) on the chemical and crystalline structures of B. mori silk are reviewed. The main emphasis is put on the crystallizable portion of silk fibroin, including its chemical constitution and its molecular conformation (at the crystallographic unit-cell level) in the two crystalline modifications : the beta pleated sheet and the silk I structures. The structural aspects are based on a discussion of X-ray and electron diffraction data, and on conformational energy analyses of a model (Ala-Gly)n polypeptide of silk fibroin.


The adaptation of the silkgland cell to the production of fibroin in Bombyx mori L. At the end of the larval life, the posterior silk gland of Bombyx mori is highly specialized in the biosynthesis of a specific protein : silk fibroin. The successive steps of fibroin production : amino supply, synthesis and secretion are described. Their analysis shows that fibroin synthesis is important enough to orient the overall cellular activities. Thus, the terminal differentiation of the posterior silk gland cell corresponds to the cells adaptation to the production of fibroin. Cytological and biochemical studies of the silk gland development show that specialization occurs discontinuously; the fourth molt, when fibroin is no more produced, is a phase of regression of the cellular adaptation whereas cell differentiation proceeds during the growth phase of the following fifth intermolt. After the spinning of the cocoon, the cells are lysed and disappear entirely at the nymphal stage. Biometrical analysis of silk production of different Bombyx strains in relation with the development of the proteosynthesis apparatus leads to the conclusion that the specific messenger RNA content determines the amount of synthetized fibroin. At maximum secretion, the mRNAF recruits almost all the cell ribosomes. The variations of the size of the proteosynthesis machinery are sufficient to explain the differences of productivity of the various silkworm strains. Different experimental factors affect silk production. Topical applications of juvenile hormone induce an increase of the RNA content and a consequent rise of the amount of secreted protein. In contrast, starvation reduces the silk production by acting at both transcriptonal and translational levels. Current researches on this system are devoted to the study of the differential gene expression, with particular interest to the regulation of the transcription of the specific fibroin messenger RNA.


Effect of starvation on tRNA synthesis, amino acid pool, tRNA charging levels and aminoacyl-tRNA synthetase activities in the posterior silk gland of Bombyx mori L. Changes in the translational machinery components of the Bombyx mori posterior silk gland were analysed during starvation and refeeding and compared to the regularly fed larvae. During starvation, tRNA and ribosomal RNA synthesis are stopped. The amounts of different RNA classes and of the different tRNA species slow down at the same rate. Thus various tRNA show similar half-lifes and the preexisting tRNA adaptation to fibroin mRNA translation persists during starvation. Similarly, the tRNA/rRNA ratio is constant during starvation and refeeding (12 tRNA molecules for one ribosome) as in silk glands of control animals. Aminoacyl-tRNA synthetases and tRNA charging levels are decreased during starvation. The maximal tRNA charging level obtained during maximal protein synthesis in control animals is regained after 24 h refeeding of starved larvae. Changes observed in the free amino acid pool are not similar from one amino acid to another and levels reached after starvation do not differ strongly from the controls. Our results suggest that the production of translation apparatus components is coordinated and adjusted to the protein synthesis activity. Whether this coordination occurs in the silk gland is discussed on the basis of the "metabolic regulation", primarily described in prokaryotes and Yeast. Transfer RNA charging levels seem to play a key role in the process of regulation and could be implicated in the mechanism of tRNA adaptation if this phenomenon results as expected from a transcriptional control.


Studies on tRNA adaptation, tRNA turnover, precursor tRNA and tRNA gene distribution in Bombyx mori by using two-dimensional polyacrylamide gel electrophoresis. Eighteen out of twenty amino acids have been used for identifying tRNAs from the silkworm Bombyx mori L. fractionated on two-dimensional polyacrylamide gel electrophoresis. 43 spots out of 53 have been identified. This mapping confirms previous results and brings new answers to some questions on the regulation of tRNA biosynthesis. 1. In addition to quantitative adaptation of tRNAs to the composition of silk proteins (fibroin from the posterior silk gland, sericin from the middle part) and of iso-tRNAs from posterior silk gland to the major codons of fibroin mRNA, we also observe adaptation of tRNA from various tissues to the average amino acid content of proteins from fat body, gut, gonads and carcass of the silkworm. 2. In the silk gland, turnover rates of several tRNA species are similar. The selective accumulation of tRNAs needed for decoding fibroin and sericin mRNAs which takes place during the Vth larval instar, cannot be explained by the occurrence of a preferential degradation of some tRNA species. 3. Under given conditions for incubating silk glands, it is possible to obtain an accumulation of precursor tRNA species, which are enriched in pre-tRNAAla and pre-tRNAGly in the posterior silk gland and pre-tRNASer in the middle part. 4. The distribution of tRNA genes is not random. tRNA genes for glycine, alanine and serine are prominent. Selective transcription of batteries of iso-tRNA genes could explain our data.


Dynamics of macromolecular populations: a mathematical model of the quantitative changes of RNA in the silkgland during the last larval instar. The quantitative changes of RNA in the silkgland of Bombyx mori have been studied during the last larval instar by using a mathematical model (Volterra-Kostitzin model). This model can be associated with a global mechanism including synthesis and degradative processes. The numerical and statistical methods used for model analysis are described in an appendix. Thus we have compared the accumulation of total RNA (essentially ribosomal) after a treatment (juvenile hormone) and between several strains. The importance of the degradative factor is denoted to explain the observed differences, whereas the synthesis rates remain relatively stable. The last observation may lead us to an interpretation of the molecular effect of a selection to increase silk production : rather than an increase of the productivity of cellular machinery, the degradative process has been limited.


Juvenile hormone modifies larvae and silk gland development in Bombyx mori. Topical application of a Juvenile Hormone Analogue (ZR 515) during the first half of the first half of the last (fifth) larval instar of Bombyx mori induces a prolongation of this instar and increases larvae weight and silk secretion. Later treatment can lead to an extra larval molt. Moreover, the hormone analogue stops either the development or the secretory activity of the silk gland, depending on the period of treatments. When Juvenile Hormone is administered at the beginning of the fifth instar, silk gland growth as well as RNA and protein syntheses are first inhibited and later resumed and amplified. Finaly silk production increases up to 150 per cent of controls. One of the primarly effects of treatments seems to be RNA synthesis. Thus Juvenile Hormone analogue application could be a new tool for studying  RNA transcription and/or processing.


Effects of contingent versus yoked temperature feedback on voluntary temperature control and cold stress tolerance. Twenty-four male internals (locus of control) and 24 externals were instructed to increase finger temperature under one of three conditions: (1) contingent feedback (CF), (2) yoked sham feedback (YF), or (3) no feedback (NF). Five 13-min training sessions were given. Feedback was then removed and subjects tested for voluntary temperature control. Finally, the cold pressor test, a laboratory analogue of natural cold stress, was administered under no-feedback conditions. Results demonstrated voluntary control of peripheral temperature following contingent feedback training, but not after yoked feedback temperature training. Contrary to expectation, the acquisition of voluntary control did not attenuate the stress response to thermal pain. Differences between internals and externals throughout the study were generally insignificant.


Heart rate and blood pressure biofeedback: II. A review and integration of recent theoretical models. The theoretical models put forth separately by Bremer, Lang, and Schwartz to account for the data on biofeedback and cardiovascular responses are summarized and evaluated in light of recent empirical studies. Although each model makes some use of the idea that learning to control heart rate, particularly heart rate acceleration, is like motor skills learning, each model also emphasizes different sets of factors or variable. An attempted integration of these three models is presented.


The effects of EMG feedback training during problem solving: a case study. The present case study investigated the effects of competing task demands on biofeedback training to reduce frontalis muscle tension. Baseline levels of frontalis muscle tension were recorded for relaxation and problem solving. The subject was trained to decrease muscle tension with biofeedback for the problem-solving task alone. The results indicated that EMG training during problem-solving was successfully accomplished. Frontalis muscle tension during relaxation baseline did not change as a result of reductions in muscle tension during problem-solving feedback training. This suggests that the decrease of muscle tension cannot be attributed to reductions in overall muscle tension levels. Instead, training was specific to the problem-solving feedback phases. Additionally, it was found that accuracy in problem-solving did not decline as a result of simultaneous feedback training. Thus EMG biofeedback training can be accomplished and exercised without disruption of ongoing mental activity.


Target training: a technique for assessing self-regulation of skin temperature. The determination of the achievement of self-regulation of hand temperature can be difficult, even with adequate baseline and control procedures. Although bidirectional training is often mentioned as a technique for thorough learning and for a convincing demonstration of temperature control, patients are sometimes unwilling or unable to lower hand temperature volitionally. This case report describes a patient who, due to failure at lowering her hand temperature, developed the target training method to convince herself of her self-regulation skill. The method may be useful in both clinical and research settings.


Evaluation and statistical judgement of neural responses to sinusoidal stimulation in cases with superimposed drift and noise. Time histograms of neural responses evoked by sinuosidal stimulation often contain a slow drifting and an irregular noise which disturb Fourier analysis of these responses. Section 2 of this paper evaluates the extent to which a linear drift influences the Fourier analysis, and develops a combined Fourier and linear regression analysis for detecting and correcting for such a linear drift. Usefulness of this correcting method is demonstrated for the time histograms of actual eye movements and Purkinje cell discharges evoked by sinusoidal rotation of rabbits in the horizontal plane. In Sect. 3, the analysis of variance is adopted for estimating the probability of the random occurrence of the response curve extracted by Fourier analysis from noise. This method proved to be useful for avoiding false judgements as to whether the response curve was meaningful, particularly when the response was small relative to the contaminating noise.


Some notes on the statistical properties of a posteriori Wiener filtering. In this study the authors analyse the asymptotic distribution of estimated a posteriori Wiener filtering of averaged evoked responses and the problem of the existence and convergence of moments of the estimated filter and the filtered signal. The authors concluded that the only justification of a posteriori Wiener filtering lies in the possibility to use it as a vehicle of a priori information.


Entrainment of oscillatory neural activity in the cat's lateral geniculate nucleus. Oscillatory neural activity in the frequency range 7-12 Hz is observed in the lateral geniculate nucleus (LGN) of the lightly anesthetized cat. This paper describes a series of experiments in which the interactions between ongoing oscillatory potentials and periodic photic and electrical stimuli are analyzed using frequency domain techniques. The principal results of these experiments are consistent with a model of the neural system as an entrainable oscillator in which ongoing oscillations are suppressed by stimulation at nearby frequencies, but coexist with stimulus frequencies farther away. The physiological interpretation of these results may be closely tied to the role of the LGN as a "gating" mechanism between retina and cortex.


A volume conductor study of compound action potentials of nerves in situ: the forward problem. A computer model for the stimulation of compound nerve action potentials, based on superposition of volume conducted single nerve fibre potentials, is presented. The model assumes that the intracellular fibre potential, the fibre diameter distribution and the electrical conductivities of different tissues are known. Volume conductor fields are calculated in the spatial frequency domain. The influence of important parameters in the model is evaluated numerically. It is shown that it is necessary to give up the usual assumption of homogeneity and isotropy in the extracellular medium. In the present model parameters are introduced which allow an overall description of the complex morphological and physiological structure of the nerve trunk. Simulation results indicate that the model is a rather promising tool in studying the main properties of compound action potentials which up till now have not been sufficiently well understood.


[Activity, isoenzyme composition, thermostability and molecular weight of peroxidase from intact and virus infected tobacco plant leaves]. The enzyme peroxidase was isolated from the leaves of the tobacco plant Xanthi (intact and infected with weakly (XY) and highly (XT) pathogenic strains of potato X-virus) and partially purified. The original extract (the 30,000 g supernatant) was purified by ammonium sulfate at 30--80% of saturation and by gel filtration through Sephadex G-25 and G-100 in 0.05 M tris-HCl buffer, pH 7.4 containing 17% sucrose. Disc electrophoresis revealed that both intact and infected plants contain 10 isoperoxidases. The electrophoregrams of isoenzymes from infected plants with the Rf values of 0.1, 0.48, 0.53 and 0.59 stained with benzidine produced a more intensive colouring as compared to the corresponding isoenzymes from intact plants. The total enzymatic activity for the plants infected with the XY and XT strains made up to 180% and 240% of that for the intact plants, respectively. The molecular weights of the peroxidase isoenzymes were found to be the same and equal to 40,000. Study of the thermostability at 60 degrees C and pH 7.0 showed that after 90 min the enzyme activity was 12.4% and 5.1% of the original one in intact and infected plants, respectively. The data obtained suggest that the activity, thermostability and synthesis of some peroxidase isoenzymes in tobacco plant leaves are affected by viral infection.


[Specificity of intracellular ribonucleases Pc1 and Pc2 of the fungus Penicillium claviforme]. The products of RNA and synthetic polynucleotides degradation by intracellular RNAses Pc1 and Pc2 of the fungus Penicillium claviforme were studied. It was shown that the enzymes possess the endonuclease activity and are not specific for the bases vicinal to the cleaved PDE bonds (EC 3.1.4.23). The increase of binding of the dinucleoside monophosphates by Pc1 and Pc2 dependent on the nucleoside at the 3'-end of the PDE bond is: A greater than C greater than G greater than U. This order is opposite for the rates of these substrates cleavage by the RNAses. A homologous specificity of the intracellular RNAse Pc1 and the extracellular RNAse II of Pen. claviforme has been revealed.


[Thermal stability of lactate dehydrogenase and alcohol dehydrogenase incorporated into highly concentrated gels]. The rate constants for inactivation of lactate dehydrogenase and alcohol dehydrogenase in solution at 65 degrees C (pH 7,5) are 0,72 and 0,013 min-1, respectively. The enzyme incorporation into acrylamide gels results in immobilized enzymes, whose residual activity is 18--25% of the original one. In 6,7% gels the rate of thermal inactivation for lactate dehydrogenase is decreased nearly 10-fold, whereas the inactivation rate for alcohol dehydrogenase is increased 4,6-fold as compared to the soluble enzymes. In 14% and 40% gels the inactivation constants for lactate dehydrogenase are 6,3.10(-3) and 5,9.10(-4) min-1, respectively. In 60% gels the thermal inactivation of lactate dehydrogenase is decelerated 3600-fold as compared to the native enzyme. The enthalpy and enthropy for the inactivation of the native enzyme are equal to 62,8 kcal/mole and 116,9 cal/(mole.grad.) for the native enzyme and those of gel-incorporated (6,7%) enzyme -- 38,7 kcal/mole and 42 cal/(mole.grad.), respectively. The thermal stability of alcohol dehydrogenase in 60% gels is increased 12-fold. To prevent gel swelling, methacrylic acid and allylamine were added to the matrix, with subsequent treatment by dicyclohexylcarbodiimide. The enzyme activity of the modified gels is 2,7--3% of that for the 6,7% gels. The stability of lactate dehydrogenase in such gels is significantly increased. A mechanism of stabilization of the subunit enzymes in highly concentrated gels is discussed.


[Denaturation of beef liver glutamate dehydrogenase under the action of guanidine hydrochloride and a study of the possibility of the enzyme renaturation]. It was shown that denaturation of beef liver glutamate dehydrogenase under the action of guanidine hydrochloride results in a diplacement of the protein fluorescence maximum from 332 to 349 nm, in a decrease of optical rotation of the protein at 233 nm and in an appearance of negative bands in the difference absorbance spectrum with extrema at 279 and 287 nm. The transition of native enzyme into a denaturated state is observed within a narrow interval of guanidine hydrochloride concentrations. The middle point of the transition corresponds to approximately 2,2 M guanidine hydrochloride. The inactivation kinetics for glutamate dehydrogenase coincide with those of the enzyme spectral properties alterations due to denaturation. The attempts at renaturation of glutamate dehydrogenase by diluting the denaturated enzyme solution or by a dialysis against a buffer solution were unsuccessful.


[Interaction of substrates and their analogs with adenosylcobalamine-dependent glycerol dehydratase]. The interaction of AdoCbl-dependent glycerol dehydratase with the substrates (glycerol, 1,2-propandiol, ethylene glycol) and their analogs (aliphatic diols) was studied kinetically. It was found that all the diols tested are competitive inhibitors of the enzyme with respect to substrates. The arrangement of hydroxyl groups in the molecule, the length of the carbohydrate chain and the nature of the substituent at the C-3 atom are essential for the binding of diol in the active center. The ternary enzyme-AdoCbl-substrate (analog) complexes are subjected to specific inactivation at a rate, which depends on the chemical structure of the substrate (analog). The constants for inactivation and dissociation of the ternary complexes were determined. It was shown that in contrast to the double complexes (enzyme-AdoCbl), the inactivation of the ternary complexes does not depend on oxygen. Some aspects of the mechanism of specific inactivation of glycerol dehydratase are discussed.


[Effect of dibromothymoquinone on photosynthetic electron transport]. The effect of dibromothymoquinone on photosynthetic electron transport in pea dependent on concentration was studied. Dibromothymoquinone inhibited general electron transport from water to NADP+ in isolated chloroplasts and ethiochloroplasts and the electron transfer via plastoquinone and cytochrome f in the leaves and isolated plastids. At all concentrations studied dibromothymoquinone significantly affected the absorption changes at 590 nm in the ethiochloroplasts associated with plastocyanine photoreactions. Possible location of electron carriers in the photosynthetic electron transport chain is discussed.


[Participation of oxygen activated species in enzymatic lipid peroxidation in biomembranes]. The participation of oxygen activated species in the induction of lipid peroxidation (LPO) in the membrane systems containing cytochrome P-450 (liver microsomes) and in the membrane fragments devoid of this hemoprotein (brain and skeletal muscle microsomes) was studied. It was shown that the rate of NADH-dependent LPO does not depend on the presence of hemoproteins and the activity of NADH-specific flavoprotein in the membranes. On the other hand, the microsomal membranes of the liver with high specific contents of b5 and P-450 cytochromes and NADPH-specific flavoprotein, had the highest rates of NADPH-dependent LPO. It was found that the most effective inhibitors of free oxygen activated species in the case of NADPH- and NADH-dependent LPO in the microsomal fractions of liver, brain and skeletal muscles are the superoxide (O ./2) anion radical inhibitors. The singlet oxygen (1O2) quenchers inhibit only NADPH-dependent LPO in the liver, however, in a far lesser degree. The hydroxyl radical (OH) scavengers had no effect on enzymatic LPO in all systems studied.


[Reconstitution of liver endoplasmic reticulum membranes from solubilized proteins and lipids by removal of detergent]. A method for membrane reconstitution from cholate-solubilized microsomal proteins and lipids by a removal of the detergent on a column with charcoal has been developed. A comparative study showed that the membranes reconstituted by a dialysis or absorption do not differ from each other in terms of membrane proteins incorporation into lipid vesicles and cytochrome P-450 reconversion into cytochrome P-450. A possibility of biomembrane reconstitution from membrane proteins and lipids solubilized by a non-ionic detergent Triton X-100 was shown. A removal of the detergent results in a formation of membranes, which are chemically close to the original ones but ultrastructurally very different from the latter. On the other hand, absorption or dialysis of cholate-solubilized proteins and lipids results in reconstituted membranes with asymmetrically arranged intramembrane particles located on the hydrophobic surfaces of the membrane halves. The number and size of these particles are similar to those of the original microsomal membranes.


[Proteinase activity of nuclei from various tissues towards endogenous histones]. The proteinase activities of nuclei isolated from tissues differing in their mitotic activities (brain, thymus, liver, ascite lymphoma) towards the histones and non-histone acid -- extractable proteins were studied. The sensitivity of different histone fractions to nuclear proteinase depends on temperature and time of nuclei incubation under conditions providing for complete dissociation of chromatin proteins from DNA (2 M NaCl--5 M urea). The proteinase activity in the brain and thymus nuclei is revealed only under prolonged (43 hrs) incubation of the nuclei at 25 degrees C, which is accompanied by partial proteolysis of histone H1. Histone H4 from brain nuclei and histone H2a from thymus nuclei are preferably degraded. In the nuclei isolated from the mice ascite cell lymphoma NK/ly and from rat liver the enzyme activity is revealed mainly towards the arginine-enriched histones H3 and H4. The proteolysis of the arginine-enriched histones in tumour cell nuclei is more complete. A high sensitivity to proteolysis was observed for non-histone acid-extractable proteins with low electrophoretic mobility, which were found in brain and tumour cell nuclei.


[Circular dichroism spectra of protein proteinase inhibitors]. The circular dichroism spectra of two protein proteinase inhibitors were studied. The CD spectrum of the kidney bean inhibitor is similar to those of other low molecular weight inhibitors from legume seeds. The potato inhibitor in its native state is characterized by a low content of alpha-helices, which is increased in the presence of sodium dodecyl sulfate.


[Properties of pig liver transketolase]. Some properties of homogeneous transketolase from pig liver were studied. It was shown that the pH optimum of the transketolase reaction lies within the range of 7.8--8.2. The isoelectric point is at pH 7.6--7.8. The molecular weight of transketolase is 138,000 +/- 3,000 as determined by the sedimentation equilibrium method and about 152,000 according to the data from gel filtration through Sephadex G-200. The enzyme molecule is a tetramer of the alpha 2 beta 2 type. The molecular weights of the alpha- and beta- subunits determined by polyacrylamide gel in the presence of sodium dodecyl sulfate are 52,000--56,000 and 27,000--29,000, respectively. Transketolase contains about two moles of TPP per mole of protein and does not require metal ions for its catalytic activity.


[Interaction of rat liver dexamethasone-receptor complexes with DNA]. Rat liver glucocorticoid-receptor complexes (GRC) acquire the ability to bind to DNA in a high affinity manner after activation by heating or precipitation with (NH)2SO4. DNA is practically non-saturable by GRC in low salt buffers as well as in 0.15 M NaCl-containing buffer, although in the latter case the binding decreases approximately 3--5 times. GRC bind to homo- and heterologous prokaryotic DNA in a similar way; in both cases an addition of KCl (up to 0.15 M) to the medium is followed by the same decrease of the binding. This data suggest that the association of GRC with DNA observed in vitro is not accompanied by "recognition" of any certain DNA site. Besides DNA, activated GRC can associate with other polymers, charged positively (DEAE-cellulose) or negatively (RNA, polyvinylsulfate). GRC interact very weakly with neutral compounds of the cellulose type but are strongly adsorbed on hydroxyapatite. Hence the activated GRC can be considered as an amphoteric protein. Salt solutions provoke dissociation of the GRC-DNA triple complexes: a complete dissociation is observed in the presence of 0,4 M NaCl or 0,4 M sodium phosphate buffer (pH 6,9). Sodium phosphate buffer also elutes GRC from other sorbents such as DEAE-cellulose or hydroxyapatite. No significant dissociation of the GRC-DNA complexes is observed at sucrose concentration up to 2 M. The data obtained are indicative of an essential role of electrostatic forces for the interaction of GRC with DNA. The non-ionic detergent Triton X-100 at a concentration as low as 0,05% completely destroys the GRC-DNA triple complexes. The models explicating the  selectivity of the genome activation by GRC without their "recognition" of any specific DNA sequences are proposed.


[Analysis of brain chromatin subunit composition using different endonucleases]. A comparison of the processes of chromatin digestion in brain and liver nuclei by Ca, Mg-dependent and staphylococcal endonucleases demonstrates a similarity of the subunit composition of chromatin from both tissues and reveals the same type of linked DNA regions. However, a formation of low molecular weight DNP fragments during hydrolysis and the DNA spectra of soluble and insoluble DNP fragments suggest that brain chromatin contains these fragments alongside with the regions, which are specific for this particular tissue, predominate in it and are resistant to staphylococcal and, particularly, to Ca, Mg-dependent endonucleases. This is paralleled with a non-histone protein enrichment of different brain chromatin fractions and an expansion of the electrophoretic monomer band towards the fragment with a greater molecular weight. It may be assumed that brain nucleosomes are characterized by a higher size heterogeneity of linked DNA, part of which are mostly covered by non-histone proteins, and/or are characterized by a greater set variety.


[Isolation and purification of bovine and porcine cerebral cathepsin D]. Cathepsin D was isolated from the grey matter of bovine and porcine large cerebral hemispheres and purified by affinity chromatography on haemoglobin--Sepharose. The isolation and purification of the enzyme also included: acidic extraction, precipitation by ammonium sulfate, dialysis, affinity chromatography, concentration and gel-chromatography on Sephadex G-100. The degree of purification of bovine cerebral enzyme was 3280. The Km value for the enzyme was 2,06 . 10(-5) M. The purified enzyme from bovine brain showed three major and two minor adjacent bands, possessing the cathepsin D activities. The purified enzyme from porcine brain showed only one protein band.


[Biochemical analysis of RNA particles and nucleolar RNases in eucaryotic cells]. Four types of rat liver nucleolar RNP particles with the sedimentation coefficients of 120S, 80S, 60S and 12--16S were analyzed and their chemical composition was established. The nucleolar RNP particles were found to contain a RNA set with the sedimentation coefficients of 43S, 33S, 20S and 7S. The nucleolar proteins were shown to contain endonucleases, one of which was isolated and partially purified by fractionation on DEAE-Sephadex A-50. In some of its properties this RNAse was found similar to an analogous enzyme from membrane-bound ribosomes.


[Isolation and properties of cytochrome P-450 from rabbit liver microsomes]. A purified low-spin form of cytochrome P-450 was isolated from phenobarbital-induced rabbit liver microsomes. The preparation was functionally active and free from cytochromes b5 and P-420 and phospholipids. The specific content of the cytochrome was 18 nmoles per mg of protein. At the molecular weight of the hemoprotein of 50,000, it corresponds to 90% of purification. The purified hemoprotein binds substrates of type II and some substrates of type I. The complexes formed reveal spectral properties, similar to those for the complexes of these substrates with the microsomal form of cytochrome P-450.


[Methylation and degradation of chromatin DNA in isolated rat liver cell nuclei]. Methylation of chromatin DNA in rat liver cell nuclei incubated in a medium with [3H]CH3-S-adenosyl methionine was studied. It was shown that under the given experimental conditions DNA methylation and chromatin degradation by endogenous nuclear nuclease (nucleases) with a formation of chromatin structural subunits occur simultaneously. An analysis of methylated chromatin DNA degradation products based on a number of approaches demonstrated a predominant methylation of extra-nucleosomal DNA. The data obtained suggest that chromatin of isolated nuclei contain sites with supermethylated DNA fragments incorporating not less than 400 nucleotide pairs. These sites possess an increased sensitivity to endogenous nuclease.


[Comparative study of cytoplasmic RNA-binding proteins of eukaryotic cells: content and polypeptide composition]. The specific RNA-binding activity of cytoplasmic extracts of a number of eukaryotic cells and tissues was determined by sorption of radioactive RNA on nitrocellulose filters. This activity varies within a wide range: from 0,5 up to 80 microgram of 23S-RNA per mg of extract protein. The percentage of RNA-binding proteins as measured by their adsorption on RNA-Sepharose is 0,3--60% of total protein of cytoplasmic extracts and is well-correlated with their RNA-binding activity. The variability of the RNA-binding activity of the isolated preparations of RNA-binding proteins (from 100 to 300 microgram of 23S-RNA per mg of protein) is indicative of their qualitative differences. The analysis of the polypeptide composition of RNA-binding proteins revealed that the set of the major polypeptide chains is rather simple (with few exceptions) and includes both universal components with mol. weights of about 36,000, 49,000 and 95,000 characteristic of a number of cells and tissues and tissue- and species-specific polypeptides. Upon differentiation of rabbit reticulocytes into erythrocytes the percentage of RNA-binding proteins is decreased 4-fold and one of the three main polypeptides with the mol. weight of about 95,000 disappears. After fecundation of sea urchin ovicelles the polypeptide with the mol. weight of 37,000 disappears from the preparations of RNA-binding proteins and at the morula stage two new components with the mol. weights of about 35,000 and 26,000 appear instead of it. The germination of wheat embryos results in a two-fold increase of the percentage of RNA-binding proteins without any essential changes of the set of main polypeptide chains.


[Properties of DNA-dependent RNA-polymerase from spleens of mice infected with Rauscher leukemic virus]. The properties of RNA polymerases A, B and C isolated from the spleens of mice infected with Rauscher leukemic virus were studied. The solubilized RNA-polymerases A and B were purified 150--300-fold. The dynamic changes in the activities of all forms of RNA-polymerases at different stages of leukosis were studied. At the earliest steps of leukosis a 2-fold increase in the RNA-polymerase B activity followed by a 5-fold increase in the RNA-polymerase A activity was observed. At late stages of leukosis the activity of RNA-polymerase C also showed an increase. The properties of RNA-polymerases A and B from the spleens of virus-infected mice were compared to those of the controls. In leukemic tissues the specific activities of RNA-polymerases A and B were higher as compared to those of the enzymes isolated from the spleens of non-infected mice. However, no significant differences in the enzyme properties in normal and virus-infected animals were revealed. Dihydrorifampicine (200 mkg/ml) caused a 50% inhibition of RNA polymerase A in vitro but had no effect on the activities of RNA-polymerases B and C.


[Biogenesis of chromatin in animal cells. Stimulation of nuclear protein and DNA synthesis in hepatocytes after brief inhibition of translation by cycloheximide]. A drastic and brief inhibition of protein synthesis (up to 95% for 3--6 hrs) by cycloheximide in the liver of rats starved for 24 hrs results in a recovery and subsequent marked stimulation of non-histone proteins, histone chromosomal proteins and DNA. The stimulation of non-histone protein synthesis was observed after 1 hr (inhibition) 12--24 hrs (recovery and stimulation of protein synthesis) and 48--60 hrs (stimulation of DNA synthesis) following the administration of cycloheximide. Two periods of histone biosynthesis were observed. The first one (24--36 hrs) was not coupled and the second one (48--60 hrs) was coupled with DNA replication. During the recovery and stimulation of protein synthesis acetylation of the histone and non-histone proteins proceeds at an increased rate. Possible applicability of the model in question for investigations of chromatin biogenesis is discussed.


[Nuclease from Aspergillus oryzae, specific for single-stranded regions of nucleic acids]. A single-stranded specific nuclease has been purified from amyloryzine obtained from the mould fungi Aspergillus cryzae. The nuclease under study resembles the enzymes described in the literature in its ability to hydrolyze single-stranded nucleic acids. However, the enzyme essentially differs from previously known nucleases in some catalytic properties, particularly in its ability for degradation of poly A. It has been shown that the enzyme also hydrolyzes the synthetic dinucleotide pTpT to mononucleoside phosphates.


[Isolation and some properties of ATP-dependent DNAse from sea urchin (Strongylocentrotus intermedius) embryo]. An ATP-dependent DNAse was isolated from the cells of the sea urchin Strongylocentrotus intermedius embryos by chromatography on DEAE-cellulose and gel chromatography on Sepharose 4B. The enzyme was found homogeneous during polyacrylamide gel electrophoresis. The molecular weight of the enzyme was determined by gel filtration through Sepharose 6B and was equal to approximately 450,000. The sedimentation coefficient as determined by ultracentrifugation was equal to approximately 15S. The pH optimum during native DNA hydrolysis lies within the pH range of 6,5--9,0 and that during hydrolysis of denaturated DNA--within the pH range of 9,0--9,5. The enzyme was activated by ATP and dATP at the optimal concentration of 10(-4) M. Other nucleoside triphosphates did not substitute for ATP in this reaction. The hydrolysis of denaturated DNA occurred via the exonuclease way with a formation of short (di-, tri,- tetra- and penta-) oligonucleotides. The enzyme hydrolyzed native DNA according to the endonuclease type with predominant formation of high molecular weight polynucleotides.


Three experiments on the effects of information frequency and feedback timing on instructed heart rate speeding. Three experiments are reported comparing different biofeedback displays in a heart rate speeding task. The first experiment examined the effects of heart rate feedback presented at three frequencies in a fixed-time format. Information was given at 0.5-sec, 2-sec and 8-sec intervals. Results indicated that both the 0.5-sec and 8-sec groups' speeding performances were superior to that of the 2-sec group. The second experiment compared a 1-sec fixed-time group with groups receiving displays in which feedback was presented synchronously with systole. Feedback was synchronized either with every heart beat or every tenth beat. The one-beat group was superior to both the 1-sec and 10-beat groups. Experiment III again presented displays which terminated with every beat or every tenth beat. However, in the previous experiment heart interval information was presented only briefly at the systole ending the sample period. In Experiment III, criterion terminations remained on the feedback screen throughout the subsequent interval. Thus, subjects did not have the additional task of attending to very briefly presented information. Nevertheless, speeding performances of the one-beat group were again superior to that attained by the 10-beat group. In all experiments a relationship between increased respiratory and skin conductance levels and heart rate speeding performances was found, suggesting that heart rate speeding was part of a generalized pattern of arousal. It was concluded that instructed heart rate speeding is highly sensitive to changes both in the frequency of feedback presentation, and to the type of display (fixed-time or heart-time) presented.


Interactions between heart rate, psychomotor performance and perceived effort during physical work as influenced by beta-adrenergic blockade. Effects of a single intravenous dose of propranolol (0,25 mg/kg body weight) were examined in 15 healthy male subjects who performed three reaction-time tasks of different complexity, while pedalling at five work loads on a cycle ergometer. Comparisons between measurements after propranolol and after injection of a placebo solution showed a pronounced reduction of heart rate and an increase in catecholamine excretion following propranolol. Comparisons of psychomotor performance showed no significan difference between the propranolol and placebo conditions. Nor did self-estimates of perceived physical and task-induced efforts reveal any significant effects of propranolol. The results support the notion that heart rate is not a prominent cue for perceived effort.


Evoked potential correlates of human information processing. The late positive component (P3) of the feedback evoked potential was investigated in two tasks: the detection of near-threshold auditory stimuli, and the estimation of 1 s time intervals. When the intensity or probability of the threshold stimuli was varied in the detection task, it became apparent that the feedback P3 was related to the 'contingent probability' of confirming or disconfirming feedback given a particular response. In the time-estimation task the relative probabiliti-s of confirming and disconfirming feedback were altered by changing the time-window wherein a response was judged correct. In these experiments it was found that the feedback P3 component was highly dependent upon the probability of the feedback, and relatively independent of its confirming or disconfirming meaning. With decreasing probability of the feedback stimuli, the P3 component became larger, later, and somewhat more frontal.


Sleep and stressor exposure in relation to circadian rhythms in catecholamine excretion. 12 healthy male volunteers spent 64 h of continuous waking under strictly controlled environmental conditions (light, food, drink, activity) in isolation from the external world. Before and after the vigil the subjects slept in the laboratory. An additional group of five participated only during day time and spent the intervening night period asleep at home. Measurements were carried out in 3 h intervals except for sleep periods. Shortly before the circadian trough and peak of adrenaline excretion respectively, the subjects were exposed to a performance stressor. Results from the vigil showed a very pronounced circadian rhythm for adrenaline excretion but none for noradrenaline excretion. For adrenaline, night-time sleep reduced excretion levels, causing an even more pronounced circadian pattern. For noradrenaline, night-time sleep caused a drop in excretion giving the impression of a circadian rhythm. These and previous results led to the conclusion that the excretion of adrenaline exhibits a self-sustained rhythm while a rhythm in noradrenaline excretion is found only when caused by external synchronizers such as sleep-wake alternation. No difference in magnitude of stress response between peak and trough was observed for any of the catecholamines. Night-time (trough) exposure completely obliterated the circadian rhythm of adrenaline excretion for the duration of the exposure. It was concluded that the normal pronounced night-time trough of adrenaline cannot be due to unavailability of adrenaline in the medulla. With respect to sleep deprivation, no effect was found on excretion levels during waking, during sleep, or in response to the stressor as deprivation progressed. Finally, there was also found to be a close temporal covariation between adrenaline excretion and both rectal temperature and self-rated fatigue (neg.).


Voluntary heart rate control: the role of individual differences. It is a frequent observation that individuals differ markedly in their success at voluntary heart rate control. Several dispositional variables have now received attention as possible sources of such individual variation. These are critically reviewed under the following headings: resting and stimulus-elicited heart rate characteristics; autonomic and cardiac perception; imagery vividness; locus of control; trait anxiety. It is concluded that the research on individual differences in cardiac control to date is contributing to a clearer understanding of the mechanisms underlying control. However, for this contribution to be sustained, research needs to service explicit hypotheses about mediating processes. The often arbitrary and atheoretical practices that characterize much of the research in the more general context of individual differences in physiological activity must be avoided.


Early selective-attention effects on the evoked potential: a critical review and reinterpretation. Recent research on the effect of selective attention on the N1, component of the evoked potential is reviewed. These studies are based on the finding of Hillyard Hink, Schwent and Picton (1973) that this component is selectively enhanced in response to attended stimuli when a very rapid rate of stimulus delivery is used. On the basis of the subsequent set of experiments, the conditions and limits of the existence of the auditory 'N1 effect' are now quite clear. Moreover, this finding has been extended to somatosensory and visual modalities. In the present review a detailed examination of these studies has suggested a re-interpretation of the N1 effect. According to this reinterpretation, it is not a 'true' N1 component which is enhanced but the effect is produced by a summation of a negative shift with the evoked-potential wave form. Under some conditions such as those involving a very fast rate of stimulus delivery, this effect commences very early, making the N1 component appear larger. It is suggested that this shift reflects orienting to, and further processing of, an input found relevant in a preliminary sensory analysis. Topographical evidence for this kind of interpretation is provided by several studies. This negative shift is, hence, associated with voluntary attention. Some of the reviewed studies have described a rather similar negative shift as a correlate of involuntary attention to rare stimuli among the much more frequent, 'standard', stimuli.


In vitro dissolution of Synthos ceramics in an acellular physiological environment. "Synthos" (beta-tricalcium phosphate) implants in bone are resorbed and replaced with endogenous bone. This investigation was conducted to study by continuous flow and static system techniques, whether or not resorption of synthos occurs by passive dissolution at 37 degrees C. Calcium and phosphates were released in a time dependent manner from synthos in calcium and phosphate free Tris-Hcl buffer (pH 7.4). Scanning electron micrographs (SEM) of buffer exposed ceramics indicated breakdown of grain structure. In contrast, levels of human plasma calcium and phosphate were not altered by ceramics. Significant amounts of 32p were absorbed by the ceramics in the first hour and 45Ca in the second hour of exposure to plasma containing the radioactive isotopes. Exposure of ceramics to plasma did not alter the levels of plasm isotopes significantly for the remaining duration of the experiment. However, breakdown of grain structure was evident in SEM's of ceramics exposed to plasma. It appears that in an acellular physiological environment, dissolution of synthos is diffusion dependent and is limited to a localized surface exchange phenonmenon.


Importance of design, control, & quantitative data in dental clinical research. The ultimate test of a restorative dental biomaterial is its performance in vivo. Often laboratory test data does not correlate directly with clinical performance, so clinical research with human patients is essential. Clinical research that obtains maximum information from a minimum number of patients must be well designed and controlled. Pilot studies are necessary to establish experimental conditions and to determine the sample size. Previous clinical studies with various restorative materials have shown that careful screening and comprehensive oral examinations of patients are necessary to insure maximum recall for evaluation. Controlled placement procedures and randomized alloy placement are extremely important. Restorations are evaluated both by the response of patients to the restorations and by trained and calibrated dental examiners using established ranking criteria. Quantitative data measured in vivo such as that obtained from stereophotogrammetry reduced the need for large patient populations. The interfacing of a computer to record patient, placement, and evaluation data assisted greatly in project management.


Implant failures in orthopaedic surgery. Common orthopaedic implant failures are reviewed in the areas of total joint replacement and fracture fixation. In particular total hip and total knee arthroplasty, intertrochanteric hip fractures and long bone fractures are discussed. Excessive motion of implant bone interfaces, stress concentrations within the implant and stress shielding of bone are implicated in implant failures.


Evaluation of the tissue response to the wear products of the hip joint endo-arthroprosthesis. The causes of tissue reaction surrounding heterogeneous materials are: cell-mediated hypersensitivity due to an implant material; infection; post-surgery hematoma, following lysis of red cells and deposition of hemosiderin; "True" implant reaction, i.e., tissue modifications produced by wear particles of components of the prosthetic devices used. The stages of inflammation due to wear particles are: phagocytosis of particles by newly formed fibrous capsule cells; lymphatic drainage of particles through the newly formed joint capsule; granulation tissue reaction in the internal surface of the joint capsule which stores non-removed particles from inadequate drainage; necrosis of granulation tissue in contacting the artificial joint surface; formation of free masses of necrotic tissue in the joint cavity; formation of new granulation tissue due to these necrotic masses and by wear particles liberated from them (the beginning of a vicious cycle); insufficient storage by granulation tissue; formation of "auxiliary" granulation tissue in the fibrous layer of the bone-cement interfaces and in the R.E.S. of the bone-marrow; bone resorption and its replacement by granulation tissue; loosening of the prosthesis.


Developments in carbon prosthetics.

Developments in carbon prosthetics. The majority of carbon-coated prosthetic devices in use today are coated with a unique form of carbon, low-temperature isotropic (LTI) carbon. The wide acceptance of this special form of carbon is a direct result of LTI carbon's demonstrated biocompatibility, its mechanical properties, and its inertness. The LTI carbon deposition process, however, places severe constraints on the size and type of substrate that can be coated. The substrates must be small so that they may be supported in a fluidized bed and further must be able to withstand temperatures in excess of 1200 degrees C. Recent technological advancements have removed the requirement that an object to be coated must be suspended in a fluidized bed and have also made possible the deposition of isotropic carbon at near room temperature. These developments expand the application of carbon-surfaced components into areas of prosthetics not previously possible. This paper describes some of the new applications and results.


Development of a shock absorbing biomedical elastomer for a new total elbow replacement design. A shock absorbing concept of a total elbow replacement is presented. The development of a polyurethane elastomer with suitable damping and vibration characteristics, and the impact tester for comparative evaluation of elastic properties are described.


Biocompatibility of apatite ceramics in mandibles. Apatite ceramics composed of synthetic hydroxyapatite, Ca10(PO4)6(OH)2 were implanted in mandibles of adults dogs. The histological observations indicated that the apatite ceramic was closely contacted with newly formed bone tissue without any rejection phenomenon up to 2 weeks. An electron micrograph of non-decalcified ultra-thin section at 8 weeks showed that the apatite ceramic was directly bonded to newly formed bone and the mineralized bone tissue was grown into the micro pores of the ceramics independent on the pore size. It seemed that the outer surface of the apatite was exchanged by bone tissue. From these results it was considered that the apatite ceramic was a successful implant material in dental and surgical fields.


Poly-HEMA sponge: a biocompatible calcification implant. Poly-hydroxyethyl methacrylate (Poly-HEMA) was investigated for biocompatibility and calcification potential. S.C. and I.M. implants and transplants to subperiosteal sites were examined. The material was judged to be tolerated by the host tissue since no inflammatory or degenerative changes were observed. This study established that calcification does occur. This calcification does not simulate bone formation; osteoblasts were not observed. The x-ray diffraction pattern resembles that of calcium hydroxyapatite.


Family studies of red-cell metabolism of pyridoxine in beta-thalassaemia. Red-cell conversion of pyridoxine to pyridoxal phosphate was measured in 12 families with thalassaemia and 2 normal families. A strong familial pattern was demonstrated and the evidence suggested that the rate of red-cell conversion of pyridoxine is an independently inherited characteristic.


Neutralization of immune complex inhibition of antibody dependent cellular cytotoxicity in vitro by Staphylococcus-aureus protein A. Staphylococcus-aureus protein A (SPA) incubated with sera containing immune complexes and effector cells increases antibody dependent cellular cytotoxicity (ADCC)and rosette formation. The enhanced ADCC and rosetting is due to SPA functioning as an IgG Fc cellular receptor. SPA binds to the Fc portion of Igg and has much greater affinity for immune complexes than free IgG. SPA bound immune complexes are blocked from attaching to the Fc cellular receptors via a competitive inhibition which neutralizes the inhibitory effect of these complexes on ADCC and rosette formation.


Surface and cytoplasmic immunoglobulin distribution during treatment of a non-excretory myeloma. A patient with non-excretory myeloma with severe clinical signs, has been assessed for cytoplasmic and surface immunoglobulins on peripheral mononuclear cells and bone marrow cells. A clearcut monoclonal pattern was found. During treatment with melphalan, methotrexate and prednisolone a clinical remission was obtained. The immunological studies were repeated during this remission and were in accordance with the clinical improvement, however the monoclonality persisted and indicated an intracellular dissocitaion of light and heavy chains. The patient died with broncho-pneumonia and marrow failure.


A study on sleep in amyotrophic lateral sclerosis. A polygraphic study of sleep has been performed on 12 patients with ALS and 12 normal controls. Neither the total duration of sleep, nor the proportion of different stages of sleep differed significantly between the patient and control groups. A variety of morphologic peculiarities were observed in certain patients: frequent and repetitive blinking movements during the waking state (under quiet, dark conditions); persistence of EMG activity during both PS and SWS; and an early appearance of marked slow delta wave activity at the beginning of sleep. We observed in patients increased PS latency, and longer and more frequent awakenings. Certain patients also showed both qualitative and quantitative abnormalities of respiratory rhythm. A longitudinal study was performed on one patient. Results are discussed in relation to the existing literature.


The effect of high glucose concentration on the proliferation and the synthesis of lipids in endothelial cells in culture. Influence of glucose concentration on growth and lipid synthesis was investigated in human endothelial cells in culture. The biosynthesis of lipids from acetate and glucose was present in endothelial cells, but a high glucose level in the culture medium failed to modify lipid synthesis. Neosynthesis in the lipidic fraction in the medium is higher when precursor is acetate compared to glucose.


Interaction of nucleic acids with electrically charged surfaces. VI. A comparative study on the electrochemical behaviour of native and denatured DNAs at graphite electrodes. Adsorption and electrochemical oxidation of deoxyribonucleic acid (DNA) at a pyrolytic graphite electrode (PGE) and a paraffin wax-impregnated spectroscopic graphite electrode (WISGE) were studied using differential pulse voltammetry. DNA is adsorbed at the surface of the graphite electrodes in a broad range of potentials including the potentials of electrochemical oxidation of DNA. Both native and denatured DNAs yield two single, well-defined and separated peaks, G and A, on the differential pulse voltammograms at the PGE and WISGE. The more negative peak, G, corresponds to electrochemical oxidation of adenine residues. Peaks G and A of native DNA occur at the same potentials as peaks G and A of denatured DNA. However, electrochemical oxidation of adenine and guanine residues at graphite electrodes is markedly suppressed in native DNA. The heights of the peaks G and A represent a sensitive indicator of the helix-coil transition of DNA. An analysis of the product of interaction of a sample of native DNA with a large pyrolytic graphite electrode in the presence of formaldehyde at approximately neutral pH did not prove changes in the secondary structure of native DNA due to its interaction with the graphite electrode. It is suggested that the decreased differential pulse-voltammetric activity of native DNA is connected with its decreased flexibility.


Scanning molecular sieve chromatography of interacting protein systems. II. Determination of large zone transport parameters by the difference profile method at low solute concentration. The experimental determination of difference profiles for the study of large zone transport processes by scanning molecular sieve chromatography is described. Using the difference profile method, the progesterone-induced purple glycoprotein of the porcine uterus was found to exist as monomeric units in high ionic environment, with a partition coefficient of 0.269, partition cross-section of 0.488, partition radius of 25 A and a molecular weight of 33,500 g/mole. The technique was further applied in examining the association-dissociation properties of oxyhemoglobin. In a high tonic environment, the partition coefficient was found to be 0.365 for dimer and the partition cross-section, 0.419; for the tetramer in low ionic strength solution, the partition coefficient was 0.275 and the partition cross-section 0.377, with a dissociation constant of 1.03 x 10(-6) mole/l. This new technique should prove applicable in (1) readily locating the centroid positions of transport boundary profiles at the lowest practible protein concentration limits, (2) demonstrating the characteristic boundary shape and concentration-dependent centroid position for an interacting solute, (3) determining the axial dispersion coefficient characteristic of solute turbulence within the gel matrix, and (4) distinguishing the boundary between low and high ionic strength solvent phases in the gel column.


Scanning molecular sieve chromatography of interacting protein systems. III. Effect of kinetic parameters on the large zone boundary profiles for local equilibration between mobile and stationary phases. Large zone reaction boundary profiles for molecular sieve chromatography as affected by kinetic parameters have been simulated for local equilibration between the mobile and stationary phases. Our studies of monomer-dimer and monomer-tetramer systems indicate that in a slowly equilibrating system, the kinetic controls operating between the mobile and stationary phases contribute most significantly to the overall boundary profile. In a rapidly equilibrating system, however, the kinetic parameters kij and kji operating in the mobile phase are the principal determinants of the reaction boundary, while the kinetic effects of kii and k-ii between the mobile and stationary phases are minimal.


Scanning molecular sieve chromatography of interacting protein systems. IV. The difference profile method as applied to the Gibbs-Duhem expression in the analysis of the dimer-tetramer equilibria of oxyhemoglobin A. The recently-developed large zone difference profile method in scanning molecular sieve chromatography is applied to the analysis of the Gibbs-Duhem expression in the tetramer-dimer equilibrium of human oxyhemoglobin A. The preferential binding term and solvation parameters of the Hofmeister anion phosphate are examined. Results indicate that as the concentration of phosphate ions increase, a hydrated phosphate is formed which enhances the association by perturbing the solvation layer of the hemoglobin molecules. The standard free energy change at a given Hofmeister anion activity of ln Ax = -3.2476 is 9.4 +/- 0.2 kcal/mole. delta G0 at ln Ax = -1.2711 is 10.90 +/- 0.05 kcal/mole, suggesting that approximately 11 kcal are required to dissociate one mole of tetramer into dimer.


Multisite proteins and randomly coiled polymeric ligands. Chain length dependence of binding constants. A model mechanism was developed for the binding of a rigid multisite protein with a randomly coiled multivalent ligand. Probabilities of the formation of chain loops between sites located at given distances at the protein were calculated by an extension of the concept of ring closure in coiled chain molecules. Expressions were derived for the dependence of overall equilibrium quantities, such as the binding constant between the protein and the ligand, on intrinsic parameters such as intrinsic binding constants, number of sites at the protein and their distances and on the chain length of the polymeric ligand. A pronounced chain length dependence of the overall binding constant was predicted even at chain lengths much longer than the size of the protein. Such a dependence was previously observed for the enzyme prolyl hydroxylase which acts on polymeric substrates like (ProProGly)n. This so far unexplained feature is quantitatively described by the model mechanism which is believed to be applicable to many other interactions of biological importance.


[Correlation of atrial and ventricular contractility. The possibility of using the atria for controlling the artificial heart]. A possibility of the artificial ventricle regulation using information on the atrial contraction is discussed. Correlations between atrial wall tension and ventricle tension as well as the pressure under radom heart rhythm variations were studied. The wall tension of the appropriate heart portion was recorded by the arched tensiometers, and intraventricular pressure under cavity catheterization by the electric manometer. The cardiac rhythm varied between 2.0 c-1 and 4.0 c-1. A correlation between the tension and interpulse interval, (correlation coefficient being 0.62 +/- 0.05) was established. The close relationships "atrial wall tension-intramuscular pressure" were observed. For such relationships the correlation coefficient changed from 0.713 +/- 0,09 to 0,874 +/- 0.02 depending on the average value of interpulse interval. It is concluded that the information on the atrial contraction can be used for artificial heart regulation.


[Hyperventilation and inhibitory synapses]. Injection of subconvulsive doses of strychnine blocking the inhibitory synapses significantly increases the reflex activity of the respiratory muscle evoked by stimulation of the sciatic nerve as well as by inhalation of hypercapnic gas mixture. Thus the inhibitory synapses prevent the extreme hypocapnia evoked by hyperventilation.


[Relationship of the activity of cardiac cholinergic mechanisms to the state of the sympathetic innervation and its noradrenaline content in hypoxia]. Preliminary sympathectomia depletes acetylcholine (ACh) in the heart of rabbits under hypoxia. In these conditions the inhibitory action of ACh on the rat isolated heart is reduced under the noradrenaline content fall, while under increase it is potentiated. Under hypoxia noradrenaline increases concentration of potassium in the myocardium, thus stimulating ACh formation and activity. It is suggested that under deep hypoxia suppression of the sympathetic mechanisms causes functional isolation of the heart from nervous effects.


[Hemoglobin, transferrin and total iron content in the blood serum in hyperoxia and during the protective action of urea]. A rise of hemoglobin concentration accompanied by an increase of the total iron in the blood serum of white mice was found under oxygen pressure of 4 atm for an hour (preconvulsive state) and 6 atm (convulsive state). Changes in correlations of hemoglobin fractions in the blood serum were detected in both stages of oxygen poisoning by disc-electrophoresis in 7.5% polyacrylamide gel. A rise of transferrin concentration under these conditions (hyperoxia) was observed. The deflections occurred were less pronounced following administration of urea to the animals before hyperbaric oxygenation.


[Hematopoietic study of rats in experiments with exchange blood replacement by an emulsion of perfluorotributylamine]. In experiments on nonanesthetized rats blood was substituted with perfluorotributyl emulsion (PFTBA). The mean volume of transfused PFTBA was 10 ml/100 g of body weight. During the period of blood replacement and the following 5 days the rats were kept in an atmosphere with increased oxygen content, and then they were placed under normal atmospheric conditions. The influence of PFTBA solution on hemopoiesis was studied in these experiments. A marked erythropoiesis activation in the bone marrow combined with expressed peripheral blood reticulocytosis was observed 6 days after the exchange blood substitution. Hemoglobin content decreased to 8.2 g% mature and immature white cell count rose; immature erythropoiesis cells were found: polychromatophilic erythro- and normoblasts (4.2% on the average). By the 13th day there was complete normalization of hemopoiesis which lasted 12 months without any significant deviations. Basing upon the results obtained it may be concluded that the PFTBA emulsion under study produces no negative effect on the animal hemopoiesis, and does not disturb the normal regulation process under conditions of the experiment conducted.


[Effect of the duration of the previous ischemia and of the mass of ischemic tissue on the state of the coagulating and anticoagulating blood systems in tourniquet shock]. In the experiments on 80 rabbits it was shown that the inclusion of the previously ischemized extremities into circulation is accompanied by elevation of coagulating potential of the blood and inhibition of fibrinolysis shortly after the tourniquet removal followed by hypocoagulation and fibrinolysis activation. These changes depend on the duration and mass of previously ischemized tissues. It is suggested that in tourniquet shock these disorders lead either to the danger of intravascular thrombosis or to hypocoagulation with secondary fibrinolysis.


[Change in the physicochemical properties of the cerebral cortical proteins in dying and resuscitation after mechanical asphyxia]. The physicochemical properties of protein postmitochondrial supernatant after gray substance of the brain homogenization undergo changes during clinical death caused by mechanical asphyxia. The shift on the densitogram occurs after protein electrophoresis in polyacrilamide gel. After sedimentation the total concentration of proteins and total activity of lactate dehydrogenase (LDH) decrease. Followiing adsorption on a DEAE-Sephadex A-50 the total fraction of nonadsorbed beta- and gamma-globulins also decreases, and the activity of LDH (3+4+5) isoenzymes falls significantly. Disturbed behavior pattern of proteins in the sedimentation and electrophoretic fields as well as changes in the sorption properties specific for varying times of clinical death, play a certain role in the development of irreversible changes in the gray substance of the brain. The adsorption and sedimentation properties of the proteins return to normal during early postresuscitation period, whereas the electrophoretic mobility of protein fractions in polyacrylamide gel remains unchanged within the first day.


[Nonspecific esterase and alpha-glycerolphosphate dehydrogenase activity and the fat content in the regenerating chicken liver]. The data on histochemical study of changes in the activity of esterases, alpha-glycerophosphate dehydrogenase and the fat content in the chick regenerating liver are presented. The accumulation of the fat in hepatocytes during the early periods of regeneration (1--5th day of the experiment) is partially conditioned by the reduction of the activity of nonspecific esterases. The maximal liver steatosis is accompanied also by an increase in the activity of alpha-glycerophosphate dehydrogenase which indicates intensification of glycolysis and synthesis of triacylglycerines (liver spare lipids) during regeneration.


[Role of the GABA-ergic systems of the brain in manifesting the activating effect of diazepam]. It was shown in experiments on rats that the selective blocker of GABA receptors bicuculline (2 mg/kg) does not decrease the activating effect of diazepam as to the reaction of self-stimulation. The GABA-mimetic muscimol (0.5 and 1 mg/kg) had no effect on self-stimulation rate, while in the dose of 2 mg/kg causing behavioral changes produced a powerful decrease in it (by 93.3%). During the combined administration of diazepam and muscimol (1 mg/kg and 0.5 mg/kg, respectively) no potentiation of diazepam effect was observed. It is suggested that diazepam-induced facilitation of the reaction of self-stimulation is not due to the alteration in the activity of GABA-ergic processes.


[Reactions of normal human and rabbit immunoglobulins with heart valve fibroblasts]. It was demonstrated using the indirect immunofluorescent technique that normal human and rabbit sera, and IgG isolated from them intensively reacted with fibroblasts of human and bovine heart valves. The results obtained with Fab and Fc fragments of IgG sugges that this reaction is due to the Fc region of the IgG molecule and related to the presence of the Fc receptor on fibroblasts of heart valves.


[Immunochemical study of the CBA mouse kidney]. Immunoelectrophoresis and agar precipitation reaction allowed one to reveal 7 antigens in CBA mouse kidney. One of them, with a relative electrophoretic mobility--0.35, is specific for the kidney. The remaining renal antigens are common to the kidney and other organs and tissues of mice. The antigens with mobility in the albumin and alpha-globulin zones proved to be serum ones. An antigen with a mobility approximating 0 is specific for the kidney and liver. An antigen with a mobility in the alpha 2-globulin zone does not seem likely to be homogeneous and, apart from broad inter-organ specificity, bears the greatest resemblance to the lungs antigen.


[Selective inhibition of the primary humoral immune response in mice with a combination of deoxycytidine with Cytosar]. Cytosine arabinoside administration in lethal doses to C57BL/6j female mice immunized with red blood cells leads, under deoxycytidine protection, to reduction of serum hemagglutinin level on day 5 without toxicosis. Simultaneous injection of the metabolite and the antimetabolite proves to be optimum.


[Erythroid precursors studied by mouse bone marrow cultivation in a plasma clot]. Two types of erythroid precursors were found by cultivation of the mouse bone marrow in the plasma clot with mouse serum and without adding exogenic erythropoietin to the culture medium. The first precursor had properties similar to the erythroid colony-forming unit (CFUe) previously described while the second resembles in its properties the erythroid burst-forming unit (BFUe). Optimal concentration of mouse serum in the culture medium was 10-15%. Clone nature of the colonies and bursts described is confirmed by linear dependence of their number on the cell concentration in the culture.


[Pathology of mitosis after cellular recovery from a metaphase block]. The experiments in Chinese hamster fibroblast-like cells have shown that the c-mitosis inducing agents (colchicine, colcemid and low temperature) produce evident stathmokinetic and radiomimetic effects. By the reversibility moment of the former the latter becomes apparent, manifesting in bridge accumulation. This form of pathology is likely to be caused by the disturbance of the cellular nucleoprotein metabolism in c-mitosis.


[Circardian rhythm of mitoses in the epithelium of the cornea after splenectomy]. In corneal epithelium of CBA mice the index of colchicine mitoses diminished after splenectomy in the day period characterized by rising mitotic activity in control animals. The duration of active phase of cell division rhythm shortened while the maximum of mitotic activity delayed in comparison with control animals. The total amount of cells entering mitosis during 24 hours diminished by 27.7% and the rate of physiological regeneration of corneal epithelium decreased.


[Effect of the balanced inhibition of DNA and protein synthesis on the in vitro and in vivo proliferative activity of the lymphocytes]. Lymphocytes isolated from the rabbit peripheral blood were irradiated in vitro with 200, 400 and 1000 r doses and cultivated with phytohemagglutinin (PHA) doses and cultivated with phytohemagglutinin (PHA) at 37 degrees C during 48 hours. In several experiments cycloheximide, inhibiting protein synthesis, was added to the cells 60 minutes before and 30 minutes after irradiation. There was no apparent difference in the viability of irradiated cells with or without cycloheximide. The ability of lymphocytes of the popliteal lymph nodes for proliferation after PHA injection into one of the hind foot-pads of the irradiated mice was studied, as well. The injection of cycloheximide or puromycin into one of the hind foot-pads immediately after irradiation of the animals augmented the proliferation of lymphocytes in this extremity in comparison with contralateral one, 1.5-2 times. Cytosine arabinoside, inhibiting DNA synthesis, was not effective under these conditions.


[Change in the dependence of lymphocyte reactivity to phytomitogens on endogenous hormonal factors in experimental bacterial lesion of the prostate]. The relationship between the blast lymphocyte transformation response (BLTR) to PHA P, Con A, PWM and 11-hydroxycorticosteroids (I) and the testosterone (II) levels in the blood plasma and the excretion of 17-ketosteroids with the urine were studied in 11 dogs with experimental urogenous prostatitis, provoked by Staphylococcus aureus, isolated from a patient with chronic prostatitis. Multiple correlation between the BLTR and hormonal factors was noted before the experiment. It was disturbed in a month and restored 2 months after the beginning of the experiment. Before the studies the relationships were mainly realized by direct correlation with 1 and 2 months after the experiment--due to the negative correlation with II. A homeostatic nature of the hormone lymphoid relationship with respect to 11-hydroxy-corticosteroids is suggested.


[Effect of lithium chloride on the thyroid gland of white rats]. The morphological and functional changes in the thyroid tissue of white rats injected lithium chloride at doses 0.5 mekv/kg and 1.0 mekv/kg (groups 1 and 2, respectively) during three weeks were studied by the radiometric, histological and biochemical methods. The radiometric, histological and biochemical methods. The inhibitory action of lithium chloride on hormonogenesis in the thyroid gland and secretion of thyroid hormones into the blood was proved to be directly related to the lithium dose and concentration in the blood. The data of intravital radiometric and morphological analysis of the organs of the 1st group animals suggest some activization of the gland function, with the secretion of the hormones into the blood being suppressed. Increased concentration of the drug inhibits hormonogenesis and secretion of thyroid hormones into the blood.


[Reparative regeneration of the rabbit cornea with the use of ethanolamine]. A lesion was induced in the central area of the rabbit cornea as deep as half its thickness, with a trepan 4 mm in diameter. As a stimulant of regeneration, ethanolamine was injected subconjunctivally and subcutaneously. In early stages the control animals showed predominant destructive processes; epithelization was completed on the 15-16th day. A rough leukoma emerged at the deficiency site. Administration of ethanolamine made the proliferative processes in the epithelium and in the ground substance of the cornea start earlier while epithelization was completed on the 10-14th day to form a hardly noteceably leukoma. Ethanolamine has proved to be an adequate stimulant in posttraumatic regeneration of the cornea.


[Effect of the thymus on hematopoietic stem cells and on their capacity for self-maintenance]. The hemopoietic cell cloning in the spleen of irradiated mice showed that thymectomy in mature animals produced no significant changes either in the CFU count or in their self-maintenance ability.