Cytochemistry of leukocytes in childhood. III. Changes of cytochemical reactions in lymphocytes in infections and during immunological reactions]

The present paper gives a report on changes of enzyme reactions, of the glycogen content, and the nucleolus picture in lymphocytes which are based on cytochemical investigations of blood smears taken from 110 children with different diseases. In 20 new-born babies the cytochemical responses of lymphocytes after triple immunization with Di-Pe-Te immunization matter were observed. The findings reveal significant changes to be found predominantly in the activity of alpha-naphthylacetate esterase, PAS-reaction and the nucleolus picture of lymphocytes in immunological reactions. No hints for specific immunological functions of lymphocytes could be detected. The changes may refer to B-lymphocytes and to T-lymphocytes.     

The reflection of different levels of the regulation of human brain activity in spectrally coherent EEG parameters]

On the basis of clinico-anatomo-electroencephalographic studies it was shown, that in early terms of cerebral trauma, at gross disturbances of the cortical functions and safety in some cases of only vital regulation, the parameters of the EEG stability or variability are of distinct information value for estimation of the functional state of patients. It was established, that changes of stability of the frequency, power, and coherent EEG characteristics correlate with different parameters of changes of the structural-functional brain organization. At this stage the greatest connection with the disease outcome reveals the EEG coherence parameters of the cortical symmetrical points reflecting the state of predominantly median formations and general brain reactions to traumatic action. In the process of restoration of disturbed neuromental functions priority prognostic significance is acquired by parameters of intrahemispheric coherence as well as by frequency-regional properties of interhemispheric asymmetry of coherence of the brain electrical processes, characterizing functional features of the lesion focus.     

Cytochrome P450 monooxygenases of DIBOA biosynthesis: specificity and conservation among grasses.

DIBOA and DIMBOA are secondary metabolites of grasses which function as natural pesticides. The four maize genes BX2 through BX5 encode cytochrome P450-dependent monooxygenases that catalyse four consecutive reactions in the biosynthesis of these secondary products. Although BX2-BX5 share significant sequence homology, the four enzymes have evolved into specific enzymes each catalysing predominantly only one reaction in the pathway. In addition to these natural reactions, BX3 hydroxylates 1,4-benzoxazin-3-one and BX2 shows pCMA demethylase activity. With respect to DIBOA biosynthesis, identical enzymatic reactions have been found in rye as compared to maize, indicating early evolution of the P450 enzymes in the grasses.     

Metabolic changes of lymphocytes and neoplastic cells in mice with Ehrlich ascites carcinoma during tumor growth

Changes in the activities of NAD⁺-and NADP-dependent dehydrogenases of lymphocytes and tumor cells were studied in mice with Ehrlich ascites carcinoma, as well as changes in the concentrations of oxaloacetate, lactate, and NAD⁺ in the course of tumor growth. During the major period of tumor growth, conditions are produced in the lymphocytes for increased intensity of aerobic reactions directed at energy reproduction combined with a somewhat decreased intensity of synthetic processes. In the tumor cells, conditions predominantly arise for intensification of plastic metabolic reactions and reactions related to anaerobic energy reproduction.     

A study on the steady-state population of poly(A)+RNA during early development of Xenopus laevis

Autoantisera against rabbit testes and rabbit ejaculated spermatozoa have been used to study the appearance of surface autoantigens during spermatogenesis. Two distinct subclasses of autoantigens have been identified: an early subclass which first appears on pachytene spermatocytes and a late subclass which first appears on differentiating spermatids. These spermatids are just beginning to demonstrate migration of the nucleus and overlying acrosomal cap to the cell periphery and changes in nuclear shape. Some autoantigens of the early subclass do not appear on spermatozoa, but those that do are predominantly found over the acrosomal region. Autoantigens of the late subclass are predominantly found over the postacrosomal and middle-piece regions of the spermatozoon. It is suggested that morphological constraints during spermiogenesis may be responsible for the regional localization of the two subclasses.     

The neurotropic effects of low-intensity electromagnetic waves in rats with different typological characteristics of higher nervous activity

The effects of the ultralow-intensity electromagnetic fields (EMF, frequency of 4200 and 970 MHz, modulated by a quasistochastic signal in the range of 20-20,000 Hz, power density 15 microW/cm2, specific body absorption rate up to 4.5 mJ/kg) on the reactions of the central nervous system (CNS) of rats with different types of behavior were studied. Some neurochemical and behavioral mechanisms of rats' reactions were investigated. It was shown that the EMF produce pronounced changes in the state and activity of monoaminergic brain systems. These changes, on the whole, correspond to the alterations at the integrative level (predominantly, of the inhibitory character).     

Participation of angiotensin II in the establishment of negative emotional reactions

In waking rats and rabbits systemically injected angiotensin II was shown to participate predominantly in the mechanisms of negative emotional reactions. The effects of angiotensin II were observed at the behavioural level as well as at the neuronal one. Depending on the dose and the time of injection of angiotensin II and its specific antagonist saralasin they inhibited or facilitated elaboration and extinction of automatized conditioned active avoidance independently of arterial, pressure changes, the pain threshold being altered. Injection of angiotensin II abolished individual behavioural reactions of the animals in response to stress factors and increased their resistability to emotional stress. The negative emotional reactions were found to induce changes of chemosensitivity of neurones of the parafascicular complex of the medial thalamus and the midbrain reticular formation during microionophoretic application of angiotensin II. A supposition is made about the increase of angiotensin II brain synthesis under conditions of emotional stress.     

Ice And The Origin Of Life

Sea ice occurs abundantly at the polar caps of the Earth and, probably, of many other planets. Its static and dynamic properties that may be important for prebiotic and early biotic reactions are described. It concentrates substrates and has many features that are important for catalytical actions. We propose that it provided optimal conditions for the early replication of nucleic acids and the RNA world. We repeated a famous prebiotic experiment, the poly-uridylic acid-instructed synthesis of polyadenylic acid from adenylic acid imidazolides in artificial sea ice, simulating the dynamic variability of real sea ice by cyclic temperature variation. Poly(A) was obtained in high yield and reached nucleotide chain lengths up to 400 containing predominantly 3′→ 5′ linkages.     

Binding of reduced and oxidized nicotinamide adenine dinucleotide to pig heart supernatant malate dehydrogenase.

The association reactions of NADH and NAD+ with dimeric pig heart supernatant malate dehydrogenase (s-MDH) have been measured at pH 6 and 8 by calorimetric and fluorescence methods, and the thermodynamic parameters describing these reactions have been evaluated. Coenzyme binding is associated with the uptake of 0.55 mol of H+/mol of NADH at pH 8 and 0.19 mol of H+ at pH 6. No significant effect of NAD+ binding on proton binding was observed. Increase in ionic strength strongly affects the free energies of binding of NAD+ and NADH. No cooperativity was observed in the enthalpy or free energy changes for binding of NAD+ or NADH. The differences in free energy of binding of NAD+ and NADH and the effect of pH on binding of NADH are entropy based. These effects are interpreted as reflecting a small number of interactions within the active site that are predominantly ionic.     

Similar distributions of repaired sites in chromatin of normal and xeroderma pigmentosum variant cells damaged by ultraviolet light

Excision repair of damage from ultraviolet light in both normal and xeroderma pigmentosum variant fibroblasts at early times after irradiation occurred preferentially in regions of DNA accessible to micrococcal nuclease digestion. These regions are predominantly the linker regions between nucleosomes in chromatin. The alterations reported at polymerization and ligation steps of excision repair in the variant are therefore not associated with changes in the relative distributions of repair sites in linker and core particle regions of DNA.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

The search for life on Mars: Viking 1976 gas changes as indicators of biological activity

Gas compositional changes in the headspace of the Viking Biology Gas Exchange Experiment can originate from biological activity as well as redox chamical reactions, sorption and desorption phenomena, acid-base reactions, and trapped gas release. Biological phenomena are differentiated from the nonbiological gas changes by their dynamical qualities, notably by the ability of the M4 medium to sustain biological activity. Medium incompatibilities, with potential microbial types in soils, are demonstrated to be ameliorated by an incubation chamber design that provides thin films of medium around particulate soil masses and salt gradients when the soil is wet from below. Two phenomena in soils, the production and consumption of hydrogen and carbon monoxide, are coupled for a newly isolatedClostridium sp. A decrease in molecular nitrogen production by denitrifying organisms in the second and subsequent incubation cycles results from competitive nitrate utilization by anaerobic organisms. All soils tested from the cold, dry desert regions of Antarctica contain predominantly aerobic organisms while only six of the twelve soils respire using nitrate under anaerobic conditions. Although dry Antarctica soils are not the best simulations of Martian anoxic conditions, their responses show that long incubation times may be needed on Mars to demonstrate biological gas change phenomena.     

Characteristics of the course of regeneration process in the muscles of replanted rat extremities

The analysis of the changes in the muscles of replanted terminals in early and late stages was made by the method of electron microscopy. In early stages neurogenic atrophy was observed which progressed due to the destructive-regenerative process caused by incomplete innervation, deepening microcirculatory disorders and, likely, autoimmune reactions.     

Changes in the EEG spectral power during perception of neutral and emotionally salient words in schizophrenic patients, their relatives and healthy individuals from the general population

To search for EEG-correlates of emotional processing that might be indicators of genetic predisposition to schizophrenia, changes in EEG spectral power during perception of neutral and emotionally salient words were examined in 36 schizophrenic patients, 50 of their unaffected first-degree relatives, and 47 healthy individuals without any family history of psychoses. In healthy persons, passive listening to neutral words induced minimum changes in cortical rhythmical activity, predominantly in the form of synchronization of slow and fast waves, whereas perception of emotional words was followed by a generalized depression of the alpha and beta1 activity and a locally specific decrease in the power of theta and beta2 frequency bands. The patients and their relatives showed a decrease in the alpha and beta1 activity simultaneously with an increase in the power of delta activity in response to both groups of words. Thus, in the patients and their relatives, reactions to neutral and emotional words were ulterior as a result of augmented reactions to the neutral words. These findings suggest that the EEG changes reflect familial and possibly hereditable abnormal involuntary attention. No prominent decrease in reactivity to emotional stimuli was revealed in schizophrenic families.     

Allogeneic cell interactions in the rat: I. Changes in the rate of cell proliferation during local graft-versus-host and host-versus-graft reactions

Cell proliferation was investigated during local host-versus-graft (HVG) and graft-versus-host (GVH) reactions in rats by means of the popliteal lymph node weight assay. Dose-response regression lines were obtained at early, peak, and late response times for both reactions. Changes in the rate of cell proliferation were demonstrated by changes in the slopes of the dose-response regression lines and were confirmed statistically. In the local HVG reaction the rate of cell proliferation was constant from early (Day +2) to peak (Day +4) response times but possibly was reduced later (Day +8), when the response was dose dependent only at low doses. In the local GVH reaction the rate of cell proliferation increased markedly between early (Day +4) and peak (Day +8) response times and then remained constant. Examination of time-response curves following the injection of a fixed cell dose confirmed these findings. In the HVG reaction lymph node weight increased linearly with respect to time whereas in the GVH reaction the increase in lymph node weight was linear initially but became exponential before peak response. These results are consistent with the concept that, whereas HVG reactions involve proliferation of one principal population of cells (host cells), GVH reactions involve proliferation of two principal populations of cells (host and donor cells). The change in the rate of proliferation occurring between early and peak response in the GVH reaction probably reflects an initial proliferation of donor cells being joined by proliferation of host cells.     

Climatic control on vegetation and sedimentary dynamics during the Miocene (Burdigalian to Langhian) in northeastern Tunisia

Palynological and sedimentological analyses were performed on Miocene sediments of North-East Tunisia in order to detect the changes in depositional environments, including those linked to eustasy, along with changes in vegetation and climate. The specific integration of palynological (pollen and dinocysts) and sedimentological (including facies analysis) data indicate that shallow marine settings persisted until the early Burdigalian–Langhian, and that open marine environments developed progressively in the late Langhian. Since the early Serravallian, deltaic environments developed under a fluctuating, but predominantly warm climate. The palynological data support a subtropical climate during the Burdigalian, with tropical conditions prevailing at the Langhian–Serravallian transition. The observed high frequency values of megathermic and mega-mesothermic pollen taxa represent the vegetation response to the Miocene climatic optimum (MCO).     

Irreversibility in unbranched pathways: preferred positions based on regulatory considerations

It has been observed experimentally that most unbranched biosynthetic pathways have irreversible reactions near their beginning, many times at the first step. If there were no functional reasons for this fact, then one would expect irreversible reactions to be equally distributed among all positions in such pathways. Since this is not the case, we have attempted to identify functional consequences of having an irreversible reaction early in the pathway. We systematically varied the position of the irreversible reaction in model pathways and compared the resulting systemic behavior according to several criteria for functional effectiveness, using the method of mathematically controlled comparisons. This technique minimizes extraneous differences in systemic behavior and identifies those that are fundamental. Our results show that a pathway with an irreversible reaction located at the first step, and with all other reactions reversible, is on average better than an otherwise equivalent pathway with all reactions reversible, which in turn is on average better than an otherwise equivalent pathway with an irreversible reaction located at any step other than the first. Pathways with an irreversible first reaction and low concentrations of intermediates (one of the primary criteria for functional effectiveness) exhibit the following profile when compared to fully reversible pathways: changes in the concentration of intermediates in response to changes in the level of initial substrate are equally low, the robustness of the intermediate concentrations and of the flux is similar, the margins of stability are similar, flux is more responsive to changes in demand for end product, intermediate concentrations are less responsive to changes in demand for end product, and transient times are shorter. These results provide a functional rationale for the positioning of irreversible reactions at the beginning of unbranched biosynthetic pathways.