Regulation of purine de novo synthesis in cultured human fibroblasts: the role of P-ribose-PP. Procedures for assaying the rate of purine de novo synthesis in cultured fibroblast cells have been compared. These were (i) the incorporation of [(14)C]-glycine or [(14)C]formate in alpha-N-formylglycinamide ribonucleotide (an intermediate in the purine synthetic pathway) and (ii) the incorporation of [(14)C]-formate into newly synthesised cellular purines and purines excreted by the cell into the medium. Fibroblast cells, derived from patients with a deficiency of hypoxanthine phosphoribosyltransferase (HPRT-) (EC 2.4.2.8) and increased rates of purine de novo synthesis, were compared with fibroblasts from healthy subjects (HPRT+). Fetal calf serum, which was used to supplement the assay and cell growth medium, was found to contain sufficient quantities of the purine base hypoxanthine to inhibit purine de novo synthesis in HPRT+ cells. This inhibition was the basis of differentiation between HPRT- and HPRT+ cells. In the absence of added purine base, both cell types had similar capacities for purine de novo synthesis. This result contrasts with the increased rates of purine de novo synthesis reported for a number of human HPRT- cells in culture but conforms recent studies made on human HPRT- lymphoblast cells. The intracellular concentration and utilisation of 5-phosphoribosyl-1-pyrophosphate (P-Rib-PP), a substrate and potential controlling factor for purine de novo synthesis, were determined in HPRT- and HPRT+ cells. The rate of utilisation of P-Rib-PP in the salvage of free purine bases was far greater than that in purine de novo synthesis. Although HPRT- cells had a 3-fold increase in P-Rib-PP content, the rate of P-Rib-PP generation was similar to HPRT+ cells. Thus, in fibroblasts, the concentration of P-Rib-PP appears to be critical in the control of de novo purine synthesis and its preferential utilisation in the HPRT reaction limits its availability for purine de novo synthesis. In vivo, HPRT+ cells, in contrast to HPRT- cells, may be operating purine de novo synthesis at a reduced rate because of their ability to reutilise hypoxanthine.


Qualitative and quantitative aspects of intercalator-induced DNA strand breaks. The intercalating agents, adriamycin and ellipticine, were previously found to produce DNA strand breaks associated with DNA-protein crosslinks in mouse leukemia L1210 cells. The current work explores the nature of the agents that produce this effect and the quantitative relationship between the breaks and crosslinks. The protein-associated DNA breaks were produced by a wide variety of intercalators in addition to the above-mentioned compounds: actinomycin D, daunoycin, ethidium and lucanthone (miracil D). Treatment with several drugs that bind to DNA without intercalation, or that inhibit DNA synthesis without binding to DNA, did not cause DNA breaks. The strand break and crosslink frequencies were quantitated by means of alkaline elution methods. The strand break and crosslink frequencies were found to be within a factor of 2 of each other over a range of concentrations of adriamycin and ellipticine. It is proposed that intercalation-induced distortion of the DNA helix leads to strand scission by a nuclease which becomes bound to one terminus of the break so as to form a DNA-protein crosslink.


The role of DNA polymerases alpha, beta and gamma in nuclear DNA synthesis. The effects of the inhibitors 2'3' dideoxythymidine triphosphate (ddTTP) and 1-beta-D-arabinofuranosyl cytosine triphosphate (araCTP) on DNA synthesis in isolated S-phase HeLa S3 nuclei have been examined. These effects are compared with the effects of the same inhibitors in partially purified preparations of DNA polymerases alpha and beta. The effect of ddTTP on partially purified DNA polymerase gamma was also tested. DNA polymerases beta and gamma were very sensitive to ddTTP whereas DNA polymerase alpha and DNA synthesis in isolated nuclei were quite resistant. The synthesis and subsequent ligation of primary DNA pieces ('Okazaki fragments') were not affected by the presence of this inhibitor. DNA synthesis in isolated nuclei and DNA polymerase alpha activity were very sensitive to araCTP whereas DNA polymerase beta was almost totally resistant to the inhibitor. The results indicate a major role for DNA polymerase alpha in DNA replication.


Metabolism of 2-amino-3-phosphonopropionic acid in rats. The metabolism of 2-amino-3-phosphono-[2-(14)C]propionic acid or 2-amino-3-phosphono-[3-(14)C]propionic acid in rats was studied in vivo and in vitro. The radioactivity in expired CO2 from the [3-(14)C]-labelled compound indicated the cleavage of the carbon-phosphorus (C-P) bond. A small amount of the [2-(14)C]-labelled compound and the [3-(14C]-labelled compound was incorporated into 2-aminoethylphosphonic acid, and polar lipid of the liver and kidney contained the 2-aminoethylphosphonic acid. The 2-amino-3-phosphonopropionic acid was not detected at the lipid level. Incorporation of the [3-(14)C]-labelled compound into a variety of metabolites including 3-phosphonopyruvic acid and 2-phosphonoacetaldehyde suggests the transamination reaction as a decomposition mechanism of 2-amino-3-phosphonopropionic acid in mammals.


Synthesis of 1-palmitoyl and 1-stearoyl phosphatidylcholines from mixtures of acyl acceptors via acyl-CoA:1-acyl-sn-glycero-3-phosphorylcholine acyltransferase in liver microsomes. The fatty acid selectivity of the acyl-CoA:1-acyl-sn-glycero-3-phosphorylcholine acyltransferase in rat liver microsomes was studied using a mixture of the [1-(3)H]palmitoyl plus [1-(14C)stearoyl molecular species of 1-acylglyceryl-phosphorylcholine. At a 1-acyl-sn-glycero-3-phosphorylcholine concentration of 0.16 mM, the enzyme exhibited a selectivity of 3.5-fold for the 1-palmitoyl over the 1-stearoyl species of the acyl acceptor and reaction velocities with linoleoyl- and arachidonoyl-CoA were 38--47% greater than with oleoyl-CoA. Lowering the acceptor concentration to 0.016 mM gave reaction rates with the polyenoic thiolesters which were 174--187% greater than with oleoyl-CoA and the 1-palmitoyl-sn-glycero-3-phosphorylcholine was preferred by 2.2, 1.6, and 1.6-fold with oleoyl-, linoleoyl- and arachidonoyl-CoA, respectively. The results support the potential importance of the fatty acid selectivities of the acyl-CoA:1-acyl-sn-glycero-3-phosphorylcholine acyltransferase towards both acyl acceptor and donor in regulating the phosphatidylcholine species formed by the reaction in vivo.


Chemical structures of mono-, di-, tri-, and tetraglycosyl glycerides in rice bran. 1. Monoglycosyl monoglyceride, mono-, di-, tri- and tetraglycosyl diglycerides were isolated from rice bran and characterized for their chemical structures. 2. Monoglycosyl monoglycerides were characterized as Gal(beta 1' leads to 3)-1- or 2-monoacyl-sn-glycerol and Glc(beta 1' leads to 3)-1- or 2-monoacyl-sn-glycerol. 3. The structures of monoglycosyl diglyceride were Gal(beta 1' leads to 3)-1,2-diacyl-sn-glycerol and Glc(beta 1' leads to 3)-1,2diacyl-sn-glycerol. Epimeric separation of the galactosyl and glucosyl glycerides was for the first time achieved by thin-layer chromatography. 4. The main diglycosyl diglyceride was shown to be Gal(alpha 1'' leads to 6')-Gal(beta 1' leads to 3)-1,2-diacyl-sn-glycerol. 5. The major structure of triglycosyl diglyceride was characterized as Gal(alpha 1''' leads to 6'')-Gal(alpha 1'' leads to 6')-Gal(beta 1' leads to 3)-1,2-diacyl-sn-glycerol. 6. The representative structure of tetraglycosyl diglyceride was for the first time established as Gal(alpha 1'''' leads to 6''')-Gal(alpha 1''' leads to 6'')-Gal(a-pha 1'' leads to 6')-Gal(beta1' leads to 3)-1,2-diacyl-sn-glycerol.


Prostaglandin production by type II alveolar epithelial cells. Prostaglandin production was studied in fetal and adult type II alveolar epithelial cells. Two culture systems were employed, fetal rat lung organotypic cultures consisting of fetal type II cells and monolayer cultures of adult lung type II cells. Dexamethasone, thyroxine, prolactin and insulin, hormones which influence lung development, each reduced the production of prostaglandin E and F alpha by the organotypic cultures. The fetal cultures produced relatively large quantities of prostaglandin E and F alpha and smaller quantities of 6-keto-prostaglandin F1 alpha and thromboxane B2. However, prostaglandin E2 production was predominant. In contrast, the adult type II cells in monolayer culture produced predominantly prostacyclin (6-keto-prostaglandin F1 alpha) along with smaller quantities of prostaglandin E2 and F2 alpha. The type II cells were relatively unresponsive to prostaglandins. Exogenously added prostaglandin E, had no effect on cell growth, and only a minimal effect on cyclic AMP levels in the monolayer cultures.


A comparison of acyl-oxyester and acyl-thioester substrates for some lipolytic enzymes. 1. A comparison of 2-hexadecanoylthio-ethane-1-phosphocholine and 3-hexadecanoylthio-propane-1-phosphocholine and their oxyester counterparts as substrates for some lipolytic enzymes was made. 2. The critical micelle concentration and the transition temperature of the synthetic substrates were compared with the values for 1-hexadecanoyl-sn-glycero-3-phosphocholine. 3. All above-mentioned compounds were deacylated by lysophospholipases. Phospholipase A2 hydrolyzed only the acyl- sulfur- and oxygenester bond in 2-hexadecanoyl-ethane-1-phosphocholine. 4. Kinetic parameters, Km and V, for hydrolysis of these substrates were determined. Km values for thioester substrates were 5--10 fold lower than for the corresponding oxyesters. Maximal hydrolysis rates were 2--5 times higher for the thioesters. 5. Hydrolysis of thioesters by phospholipase A2, lipase and lysophospholipase was shown to proceed by an S-acyl cleavage mechanism. 6. Beef liver lysophospholipase II was rapidly and stoichiometrically inactivated by diisopropylfluorophosphate and bis(p-nitrophenyl) phosphate. Inactivation by the latter inhibitor showed burst-like kinetics. 7. Attempts to show burst-kinetics during the pre-steady state hydrolysis of 2-hexadecanoylthio-ethane-1-phosphocholine by lysophospholipase II were negative. These results are interpreted to indicated that a step prior to deacylation of the enzyme is rate-determining.


Variations in mitochondrial monoamine oxidase during progressive starvation in the brain of developing rats. Effects of progressive starvation of 12, 24, 48 and 60 h upon brain mitochondrial monoamine oxidase activity were studied. The enzyme activity was determined by three different substrates: 14C-labeled tryptamine, dopamine and kynuramine. With dopamine as substrate, the enzyme activity showed decline during 24 and 48 h of starvation. Monoamine oxidase when determined by tryptamine as the substrate, showed a decrease after 60 h of starvation. The use of kynuramine as substrate also produced a decrease in enzyme activity after 48 and 60 h of starvation. Refeeding the 60-h-starved rats for the following 24 h resulted in further decrease of monoamine oxidase activity of brain mitochondria from the 60 h starved values. The results suggest that oxidative deamination of biogenic amines is greatly inhibited during progressive starvation and remains low even after feeding the 60 h starved rats for 24 h.


Chemical and enzymic degradations of nucleoside mono- and diphosphate sugars. I. Determination of the degradation rate during the glycosyltransferase assays. In incorporation experiments used for the determination of glycosyltransferase activities, we demonstrated that the nucleoside diphosphate sugars are decomposed in three different ways: 1, transfer of the monosaccharide to acceptor molecule, catalyzed by glycosyltransferases; 2, degradation of the glycosyl nucleotides by nucleotide pyrophosphatase into monosaccharide 1-phosphates which are further hydrolyzed into free monosaccharides by phosphatases; 3, chemical decomposition of UDP-D-[14C]Gal; UDP-D-[14C]Glc and UDP-D-[14C]GlcUA into 1,2-cyclic phosphate derivatives of the corresponding monosaccharide. All the breakdown products of the nucleoside mono- and diphosphate sugars which are obtained during the incorporation experiments may be separated by paper chromatography and their amounts may be determined. Galactosyltransferase assays on human and rat serum have shown that the three different ways of decomposition of the nucleoside diphosphate sugars are dependent mostly on the concentration of divalent cations (Mn2+, Mg2+). Inhibition of the nucleotide pyrophosphatase activity is obtained with low concentrations of UMP, but increasing concentrations of UMP inhibit also the galactosyltransferase activity and consequently enhance the formation of galactose 1,2-monophosphate. A partial elimination of the nucleotide pyrophosphatase activity was achieved by the addition of increasing concentrations of UDP-D-Gal. These results demonstrate that the determination of glycosyltransferase activities in tissues and in biological fluids is not possible without a concomitant determination of the nucleotide pyrophosphatase activity present in the assay.


Elevated levels of a calcium-activated muscle protease in rapidly atrophying muscles from vitamin E-deficient rabbits. A Ca2+-activated proteolytic enzyme that partially degrades myofibrils was isolated from hind limb muscles of normal rabbits and rabbits undergoing rapid muscle atrophy as a result of vitamin E deficiency. Extractable Ca2+-activated protease activity was 3.6 times higher in muscle tissue from vitamin E-deficient rabbits than from muscle tissue of control rabbits. Ultrastructural studies of muscle from vitamin E-deficient rabbits showed that the Z disk was the first myofibrillar structure to show degradative changes in atrophying muscle. Myofibrils prepared from muscles from vitamin E-deficient rabbits showed partial or complete loss of Z-disk density. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that the amount of troponin-T (37 000 daltons) and alpha-actinin (96 000 daltons) was reduced in myofibrils from atrophying muscle as compared to myofibrils prepared from control muscle. In vitro treatment of purified myofibrils with purified Ca2+-activated proteolytic enzyme produced alterations in myofibrillar ultrastructure that were identical to the initial alterations occurring in myofibrils from atrophying muscle (i.e. weakening and subsequent removal of Z disks). Additonally the electrophoretic banding pattern of Ca2+-activated proteolytic enzyme-treated myofibrils is very similar to that of myofibrils prepared from muscles atrophying as a result of nutritional vitamin E deficiency. The possible role of Ca2+-activated proteolytic enzyme in disassembly and degradation of the myofibril is discussed.


Endocytosis in adenosine triphosphate-depleted erythrocytes. The extent of membrane invagination or endocytosis in intact erythrocytes was quantified by measuring the loss of acetylcholinesterase activity. Primaquine-induced endocytosis was completely inhibited in ATP-depleted cells. However, chlorpromazine and vinblastine were capable of inducing membrane invagination in depleted cells. With both drugs, the loss of enzyme activity was less than that measured in fresh cells. We conclude that drug-induced endocytosis is not necessarily an energy-dependent process.


Metabolism of exogenous N-acetylglucosamine in extracts of rat kidney, liver and hepatoma. 1. The metabolism of exogenous N-acetylglucosamine (GlcNAc) in rat kidney extracts was greatly stimulated by fructose 1,6-diphosphate (Fru-1,6-P2) and to a lesser extent by phosphoenolpyruvate. They served as a generator of ATP. Under these conditions, the majority of metabolized GlcNAc was recovered in the form of glycolytic intermediates. 2. The metabolism of exogenous GlcNAc in rat liver extracts was stimulated by phosphoenolpyruvate but not by Fru-1,6P2. With phosphoenolpyruvate present, most of the metabolized GlcNAc was recovered as sialic acid. 3. The metabolism of exogenous GlcNAc in rat hepatoma (AH-130) extracts was stimulated by Fru-1,6-P2 and to a lesser extent by phosphoenolpyruvate. Even with phosphoenolpyruvate present, the synthesis of sialic acid was extremely small. In these respects, hepatoma extracts resemble kidney extracts rather than those of liver.


Metabolism of 2-amino-3-phosphono[3-14C]propionic acid in cell-free preparations of rat liver. Incubation of 2-amino-3-phosphono[3-14C]propionic acid with cell-free preparations of rat liver yielded labelled 3-phosphonopyruvic acid, 2-phosphonoacetaldehyde, 2-aminoethylphosphonic acid and acetaldehyde. No radioactivity was found in phosphoenolpyruvate, pyruvic acid, alanine, and phosphonoacetic acid. When added to the cell-free preparations, 3-phosphonopyruvic acid trapped the radioactivity, resulting in decrease of incorporation of the radioactivity into 2-phosphonoacetaldehyde, 2-aminoethylphosphonic acid and acetaldehyde. Incorporation of the radioactivity into 2-aminoethylphosphonic acid and acetaldehyde was also decreased by 2-phosphonoacetaldehyde. Thus it appears that the main metabolic pathway of 2-amino-3-phosphonopropionic acid is deamination to produce 3-phosphonopyruvic acid which is, in turn, converted to 2-phosphonoacetaldehyde by decarboxylation, followed by both dephosphonylation and amination of the aldehyde to give acetaldehyde and 2-aminoethylphosphonic acid, respectively.


Channelling of exogenous phenylalanine to the sites of storage and the sites of alkaloid and protein biosynthesis in Penicillium cyclopium. Externally applied L-phenylalanine rapidly equilibrates with the cytosolic pool(s) in hyphae of emerged cultures of Penicillium cyclopium. If not incorporated into protein it is accumulated in the so called expandable pool, which is presumably localized in the vacuolar compartment. At high concentrations of exogenous L-phenylalanine practically all of the amino acid needed for protein synthesis comes from the extracellular source, contrary to alkaloid synthesis which under all conditions recruits more than 90% of the required L-phenylalanine from intracellular sources. Two pathways of alkaloid labelling can be distinguished, by which externally applied L-phenylalanine reaches the sites of alkaloid synthesis: (1) a direct way from cytosolic pool (primary labelling) and (2) an indirect way via the expandable pool (secondary labelling).


Multi-origins of milk serum albumin in the lactating goat. L-[U-14C]Leucine was infused into the right-hand mammary glands of lactating goats. Milk from both glands of the animals was sampled at intervals for 36 h. After 3 h the specific activity of milk serum albumin from the infused glands was more than six times that from the non-infused glands. The specific activity of milk serum albumin was considerably lower than that of alpha-lactalbumin or beta-lactoglobulin which are exclusively synthesized by mammary secretory cells. Following the intravenous injection of 125I-labeled serum albumin, maximum specific activity of this protein appeared in milk in 12 h. The specific activity of serum albumin in milk attained no more than 45% of the specific activity of the serum albumin in blood. It is concluded that milk serum albumin has multiple origins and that a portion of it, at least (10-20%), is made in the mammary gland.


Photodesmosine, an isomer of desmosine obtained by photolysis of this amino acid in ultraviolet light. Desmosine and isodesmosine are two isomers representing the main crosslinks of elastin. We describe a new isomer, photodesmosine, which is produced by the photolysis of desmosine at 254 nm. The mechanism of this photolysis is described and is shown to consist of two competing paths. After opening of the pyridinium ring to give a tetrasubstituted aminoketone, this compound can either be hydrolysed to give lysine and a trisubstituted analogue of glutaconic aldehyde or undergo a recyclisation and rearomatisation to give a pyridinium compound substituted in positions 1, 2, 3 and 4. An understanding of this mechanism is important in order to use photolysis as a specific method to break elastin cross-links. Although only desmosine and isodesmosine have been reported in purified elastin, the chromatographic properties of photodesmosine suggests that if other natural isomers exist in this protein they could be eluted from an ion-exchange resin at much earlier times than those observed in the case of the two already described cross-links.


Spectral characterization of the neuronal pigments of Aplysia juliana. Spectral analysis at liquid N2 temperature of the circumesophageal ganglia of Aplysia juliana showed that carotenoids and a hemoglobin-like pigment are contained in concentrations of approx. 25 and 3 micronM, respectively, in the whole ganglia. Microspectrophotometrical measurements of Aplysia neurons indicated that the carotenoids reside on lipochondria in a concentration of approx. 38 mM. In addition to lipochondria, two types of pigmented particulate having absorption maxima at about 512 and 525 nm, respectively, were found in the neurons. The neuronal carotenoids consist of violaxanthin, beta-carotene and one minor component; among them the first occupies approx. 77% of total carotenoids. Two principal absorption maxima of the carotenoids, when existing in both ganglial homogenates and Triton X-100 extracts, show a red shift of 10 nm compared with those of free pigments in hexan. The red shift may be interpreted as due to the solvation of the carotenoids by surrounding lipids.


An oligosaccharide component in proteoglycans of articular cartilage. Two types of sialic acid-containing component are released from articular cartilage proteoglycan monomer (D1) treated with 0.05 M NaOH containing 1 M NaBH4. The smaller component, which has not been described before, contains galactosamine, glucosamine, galactose and sialic acid (Molar ratio 1:1:1:2). It is eluted from ECTEOLA-cellulose with low molarity (0.4 M) sodium formate and has Kav of 0.70 on Bio-gel P30. Its presence on the proteoglycan monomer was demonstrated at all stages of foetal and adult life.


Increase in liver acid lipase of thyroidectomized rats by thyroid hormones and its inhibition by actinomycin D. Acid lipase activity in the livers of thyroidectomized rats is increased by administration of L-thyroxine. The response is dose-dependent and can be demonstrated within 12 h after treatment. L-Triiodothyronine also evokes a rapid increase in acid lipase activity, and this increase can be inhibited by coadministration of actinomycin D.


[Localization of adenine components in chick myofibrils by the ferritin antibody technic]. The immunochemical method has been proposed to indicate the adenin compounds in isolated myofibrils of striated muscle. Adenosine--containing antigen was prepared by coupling adenosine with bovine serum albumin (adenosine--BSA). Antibodies against adenosine--BSA were labelled by ferritin. The sites of the antigen antibody reaction were marked by localization of ferritin molecules. Ferritin antibodies were found to concentrate in the following sarcomere sites: M and Z bands, N-lines and terminal cisternae of sarcoplasmic reticulum near the Z-bands.


[Measurement of the magnetic relaxation of water molecules in biological systems by the impulse NMR technic with calculation of their volume]. Impulse sequences are presented for selective by biological system volume measurements of the times of spin--spin, spin--lattice relaxation of water molecules by means of NMR spin echo. Selectivity of the programs is based on the fact that in the presence of magnetic field impulse gradient diffusion quenching of the echo differs for water molecules limited or unlimited in their diffusion displacement by some barriers (membranes) and it also differs for molecules limited in compartments of different size. Selective measurement of the times of spin--spin relaxation (T2) of water in intracellular structures of the yeast cells gave the value 24.4 msec, which is 1.3 times lower than the specimen volume measured by standard method.


[Impulse propagation in an active unidimensional medium with a trigger-type region of nonuniformity]. Effects are considered which appear during impulse propagation along the active line, some elements of which are converted from the expecting regime to the trigger one. At the set length of the non-uniformity the critical value of the parameter exists, up to which the propagating impulse "takes no notice" of the trigger region. When the parameter values are higher than the critical value, the trigger region starts to generate the propagating impulses. In pathological working regimes of biological excitable media such non-uniformity may induce fibrillation.


[Theory of kinetic schemes. Random walks]. During special selection of self--functions of states methods of the kinetic scheme theory can be extrapolated on some probability processes. General solutions can be obtained with these methods, for the problem of casual wanderings in manymeric lattices for example. The general result of the work--distribution of average lifetime of a population in states is in the general case determined only by the topology of the scheme and is independent of the form of self-functions of states.


[Mathematical model of a two level ecosystem]. The model which consists of two trophical levels is developed. The species here are connected by "pray--predator" relationship. If one supposes rather narrow specialisation of predator and introduces the "ecological space", the model which was preliminary recorded as a system of common differential equations of great dimension can be modified to the system of two non-linear equations in partial derivatives. Linear approach was investigated analytically, the previous nonlinear problem was calculated on a computer. The most interesting result here is an appearance of space--time oscillations in the system, which can be regarded as the first stages of ecological succession.


[Stability of spatially-nonhomogeneous stationary conditions of a diffuse system. Positional differentiation]. The results of general investigation presented at the previous paper [9] are applied to interpreting the spatial ordering upon positional differentiation at the development of multicellular organisms. The very form of local dynamics is not specified for the lack of sufficient information about the mechanisms of biosynthesis regulation in multicellular organisms. Instead of the dynamics of intercellular processes is supposed to provide the existence of two stable stationary states. These stable regimes are interpreted as the different specialisations of individual cell (differentiations). There are accepted the boundary conditions in the form of non-zero morphogen fluxes. The requirement of stability of the exfoliated structure at the multicellular ensemble connects some physical chemical parameters of the system (the permeability of the boundaries, characteristic time of intercellular dynamics, the diffusion coefficient of morphogen and some others) in the form of inequality. Within the framework of dynamical model the ability of morphogenetic system to the regulative development is discussed.


[Sublicons containing amino acids and nucleotides]. Sublicons have been obtained. Sublicons are threadlike structures appearing during sublimation of frozen solutions of small concentrations, containing racemate mixture of amino acids and nucleotides. It is suggested that close location of chains and their zonal distribution by the section of helix spire forming sublicon wall, should provide the formation of stereohomogenous and complementary successions of biomonomers of different clases.


[Fiber interaction during impulse propagation in smooth muscle and myocardial tissues. Electrotonic interaction]. Electrotonic potential appearing in a single muscle fibre during excitation spread was calculated in the mathematical model of closely packed parallel fibres. Electrotonic depolarization values for heart and smooth muscle were shown to be 10--20 mV, that is comparable to the excitation threshold value. Tissue parameter values were estimated where the coupling coefficient was maximal. The parameter values proved to be similar to those measured in heart and smooth muscles. The data obtained indicate that the electrotonic interaction of muscle fibres should play a significant role in excitation conduction.


[Formation of fluorescent products in mitochondria exposed to UV-light]. UV-irradiation of mitochondrial membranes causes formation and accumulation of fluorescing products in the course of incubation, like it takes place during the initiation of peroxide oxidation by the iron--ascorbate system. The rate of the change of mitochondria fluorescence and the level of TBA-products in them do not correlate, which points to the difference in the formation mechanisms of these products in the course of incubation. However, a correlation is observed between the initial fluorescence intensity and the number of TBA-active products in mitochondria, which increases with the increase of the time of UV-irradiation.


[Calculation of the quaternary structure of the alpha--beta-dimer of hemoglobin]. The calculation of the structure of haemoglobin alpha--beta-dimer is performed. Calculation is divided into two steps: at the first step highly hydrophobic regions of the subunit surfaces which can provide the stability of the complex are found; at the second--the fitting of this surface regions is carried out. The calculation has resulted in finding three most stable structures. R. m. s. deviation of the positions of C beta-atoms of one of these structures from those in the native one is 3.5 A.


[Temperature characteristics of an object during the process of cryofixation by the "freeze--etching" technic]. When using low temperature methods for preparing water-containing objects in electron microscopy temperature characteristics of different objects was studied during freezing and defreezing depending on different preparation conditions. Temperature characteristics of the object was estimated by means of a storage oscillograph with a thermocouple connected through a transistor amplifier. The thermograms permit one to select preparation conditions of the object eliminating artefacts.


[Effect of adaptation conditions on slow induction of fluorescence in the leaves of higher plants]. Fluorescence induction was studied in the leaves of higher plants in vivo under normal physiological conditions according to the time of dark adaptation and preillumination conditions under the effect of red light (lambda = 650 nm) and light which stimulated the photosystem I (lambda = 700 nm). At pre-illumination of the PS I the dark adaptation curve has an extremal character which points to a process developing for 6--8 min in the darkness. Such processes may proceed in the system of biochemical reactions after PS I.


[Reaction of fluorescent labeled analogs of the antibiotic distamycin A with synthetic polydeoxyribonucleotides]. Interaction of DNA with the analogs of the antibiotic distamycin A having different numbers of pyrrolcarboxamide units and labeled with dansyl was studied. The intensity of fluorescence of these analogs increases markedly when they bind to DNA. It is shown that the introduction of dansyl into the analog molecules does not change their binding characteristics. The binding isotherms of the analogs to synthetic polydeoxyribonucleotides were obtained. Analysis of the experimental data leads to the following conclusions: 1. The free energy of binding of the analogs to poly(dA1 . poly(dT) depends linearly on the number of pyrrolcarboxamide units in the molecule of the analog whereas attachment of each pyrrolcarboxamide unit produces change of 2 kcal/mole in the free energy. 2. Attachment of a pyrrolcarboxamide unit to GC pair results in the free energy change of 0.95 kcal/mole. 3. Adenine and thymine are close but not equivalent by the energy of binding to the analogs of distamycin A. 4. The binding of analogs to poly(dA . poly(dT) is a cooperative process, presumably dependent on the conformational changes induced by the binding of analogs to DNA.


[Several possible conformational states of a homogeneous elastic polymeric chain]. A homogenous elastic macromolecule, the so-called persistent model is considered. Possible initiation of dense globular state in it with nematic orderliness of the chain elements is analysed. The entropy of such a system in an arbitrary state is calculated. It is shown that a relatively short rigid chain forms a thoroidal structure. With the chain elongation thor is increased, without changing its proportions. When the parameters are changed the thoroidal structure may turn into the conventional one-linkage one. Possible application of this model for solving the problem of trimeric package of nuclei acids is discussed in a few words.


[Stages in the thermal denaturation of spiral fragments of myosin]. Scanning microcalorimetry is used to study heat denaturation of myosin "tail" helical fragments, light meromyosin and the LF-3 subfragment. It has been shown that all the data obtained were well explained by the existence of a set of quasi-independent cooperative regions. Probable location sites of separate cooperative regions in the helical part of the molecule are indicated. The obtained places of cooperative "breaks" are in a good agreement with the places of predominant cleavage of the myosin tail by proteolytic enzymes at its limited hydrolysis. The total denaturation enthalpy for each of the helical fragments per hydrogen bond at 100 degrees C is slightly less (5.4 +/- 0.8 kJ . mol-1) than the corresponding value for globular proteins.


[Study of vesicular lipid membranes by the ultrasound method]. The elastic properties of vesicular lipid membranes using high precision ultrasound velocity measurements in egg lecithin bilayer liposomes suspensions were studied. The temperature and K2SO4 concentration dependence of the hydrophobic part of the membrane elastic properties were obtained. The ionic strength dependence is shown to be linear and to change its sign at 27.5 degrees C. The value of molar volume of egg lecithin molecule hydrophobic part as calculated from acoustical and volumetric data is equal to (665 +/- +/- 63) cm3/mol and its adiabatic compressibility is equal to (58.7 +/- 5.9) . 10(-12) cm2/dyne.


[Chlorophyll-photosensitized reduction of methyl red in detergent solutions]. Chlorophyll-photosensitized reduction of methylene red with ascorbic acid was studied in micellar solutions of triton X-100. The maximum value of photosensitization was observed in the region 0.1% of triton, approximating the critical concentration of micelleformation. The rate of photoreduction of methylene red was strongly influenced by the medium pH, the optimal pH value being 4.8. The specific activity of chlorophyll in the course of photosensitization was shown to depend on its concentration. Specific activity of the monomeric form of chlorophylls a and b (5.3 and 3.2 s-1 respectively) was estimated.


[Effect of morphine and its derivatives on the electric conductivity of artificial phospholipid membranes]. It has been shown that morphine, codeine, dionine and nalorphine do not change significantly the electroconductivity of bilayer lipid membranes (BLM) in the presence of potassium ions in the medium. Changes in BLM phospholipid composition, KC1 and opiate concentration in the medium, as well as the ratio between ionized and unionized forms of the narcotics do not affect the conductivity of lipid bilayers. A conclusion is made that morphine derivatives do not produce immediate effect on membrane potassium permeability.


[Interaction between ricin hemagglutinin and its ligands, galactose and lactose. Microcalorimetry and equilibrium dialysis]. The interaction of Ricinus communis hemagglutinin with galactose and lactose has been studied by means of microcalorimetry, equilibrium dialysis and analytical ultracentrifugation. A first class of beta-galactoside-binding sites involves two similar and independent sites of which affinity constants are 2600 M-1 for galactose and 26700 M-1 for lactose at 25 degrees C. The binding of one galactose or one lactose molecule leads to enthalpy changes of--12.3 Kcal and--11 Kcal, respectively. Considering the negative entropy changes of the association, and as for ricin, the binding of galactosides with hemagglutinin is driven by favorable enthalpic contributions. In presence of high lactose concentrations, a second endothermic step of the calorimetric titration curve was observed. This result and the biphasic nature of Scatchard plots of equilibrium dialysis suggest the existence of a second class of binding sites on the lectin molecule. As  for ricin, the interaction between these secondary sites and lactose would be entropically driven.


[Energy migration processes and electron transport during photosynthesis in higher plants: the reinforcement effect and action spectrum]. Enhancement effect on photosynthesis were calculated on the basis of the set differential equations describing the processes of energy migration and electron transport. The numerical integration of these equations was made for different kinetics parameters of the electron transport chain and under various intensity and spectral composition of actinic light. This model describes the action spectra for oxygen evolution and photooxidation of P700 in higher plants.


[Relationship between the electron structure of phosphates and the problem of ATP synthesis and utilization]. The nature of macroergic bonds and some problems of ATP formation and utilization are considered in terms of electron structure of phosphates. The main acting compound in the ATP synthesis and in the reactions of transfer and utilization of the energy of macroergic bonds as well, is ATP terminal phosphate or phosphoryl group which in the free state is a monomeric methaphosphate-ion. High reactive ability of monomeric methaphosphate-ion, its affinity of lown electrom pairs is conditioned by the presence of a vacant sp3-orbitals in phosphor atom of methaphosphate-ion. Therefore in the reactions with ATP participation the phosphoryl group plays the role of electrophilic agent. Formation of intermediate methaphosphate-ion preceding the synthesis of ATP from ADP during substrate phosphorylation results from the breakage of O--P bond, during which both electrons which form the bond stay in the oxygen atom. Another possible pathway of methaphosphate-ion formation is the ejaction of the electron from ortophosphate dianion with the help of suitable acceptor of the electrons, by light-stimulated pigment system of chloroplasts or chromatophores or singlet oxygen liberated during the decomposition of hydrogen peroxide with catalase. Due to the redistribution of electron density in the phosphate radical the latter turns into the monomeric methaphosphate-ion bound to ADP with the formation of ATP.


Decarboxylation and carboxylation of pyruvate in the living mice. Mice received intravenously [1- or 2-14C]acetate, [1-, 2- or 3-14C] or [2-14C]pyruvate and were killed 1, 3, 5 or 15 min later. The radioactivity of CO2 or HCO3- of liver or carcass as well as the radioactivity of blood glucose were measured. The ratio of the radioactivity found in these compounds after [3-14C] or [2-14C-A1pyruvate injection suggests that in the fed aminals: 1. the decarboxylation of the pyruvate was more rapid than its carboxylation, 2. most of the neosynthesized glucose was derived from pyruvate molecules which had undergone a decarboxylation followed by a condensation to citrate, 3. 1/4 to 1/3 of the pyruvate was carboxylated and 2/3 to 3/4 was decarboxylated in animals receiving a diet poor in fats.


[Stoichiometry of calcium transport by sarcoplasmic reticulum: utilization of p-nitrophenylphosphate as an energy donor]. We have studied, under different conditions and through the hydrolysis of p-nitrophenylphosphate, the stoechiometry of the active transport of calcium by sarcoplasmic reticulum. According to a minimal kinetic model, it is possible to explain the variation of the coupling factor n(t) during the calcium accumulation in absence of precipitating agent. Under the described experimental conditions, at the beginning of the experiment, the coupling factor's value is slightly above 2.


Interaction between the Ricinus sanguineus agglutinin and receptor sites isolated from normal human lymphocytes. Solubilized surface proteins from normal human lymphocytes were obtained by mild trypsin digestion. The binding of membrane components to labelled Ricinus sanguineus agglutinin (molecular weight = 120,000 daltons) was studied by a gel filtration method. The bound and unbound lectin amounts were determined from the gel filtration patterns. The binding parameters were calculated from Scatchard plots. They were compared to the parameters obtained at the same temperature for the lectin-intact lymphocyte system. The respective values for the affinity constant, were 3.5 x 10(6) M-1 and 6 x 10(6) M-1. The calculation of the number of sites per cell in each system specifies the yield of the trypsin digestion.


[Role of acetylcholinesterase in the transmembrane transfer of anions in erythrocytes]. Data are presented in favour of the regulatory role of AChE in passive transmembrane transfer of anions: 1) gradual inhibition of the enzyme with proserin brings about the change of the transport activation energy and irregular shift of temperature in the salient point on Arrhenius curves; 2) complexing of different AChE inhibitors (succinyl cholinechlorine, tetraethyl ammonium, tetramethyl ammonium, d-tubocurarin, proserin) results in the change of transport velocity. A significant increase of membrane binding of highly efficient and specific inhibitor of SITS anion transport forming complexes with membrane transport sites under the effect of acetylcholine AChE substrate is recorded. Proserin acts in the same direction, but to a much lesser degree. The removal of acetylcholine effect which activates SITS binding with the AChE inhibitor points to the initiation of structural disturbances from this enzyme. The scheme of AChE regulatory effect is suggested: modification of the enzyme conformation at the interaction with the inhibitors or substrate--structural rearrangement of the membranes--modulation of anion channels.


Chemical and physical properties of human bronchial mucus glycoproteins. Human bronchial mucus glycoproteins of different chemical types were isolated by Ecteola and gel exclusion chromatography. Chemical analysis indicated polydispersity with regard to content of sulfate and sialic acid. No blood group A, B or H activity was found in these glycoproteins. Compositions are reported for amino acid and sugar residues for several fractions obtained from both cystic fibrotic and chronic bronchitic mucus. It is noteworthy that glycoproteins extracted from a single subject contain molecules with different acid groups as well as significant differences in carbohydrate chain length.


Is a metabolic control for the doubling of the macromolecule synthesizing machinery possible. The usual models for cell multiplication only involve macromolecular events and ignore the influence of metabolism. The conjecture presented here shows how metabolism could be involved. Separate pathways might cooperate for the synthesis of a small molecule, acting as positive control of several macromolecular syntheses, including stable RNA synthesis. A detailed analysis of the available data showing an influence of metabolites on macromolecular syntheses suggests that two main pathways might cooperate, one involving serine and folic acid metabolism and the second involving threonine and the branched chain aminoacids. Experiments are suggested to challenge the conjecture.


Evidence for the glycoprotein nature of radish beta-fructosidase. Concanavalin A (Con A) was utilized free, bound to Sepharose 4 B or cross-linked to glutaraldehyde to investigate the possibility of binding this lectin to radish beta-fructosidase (E.C.3.2.1.26). The choice of cross-linked Con A as affinoadsorbent is discussed and standard conditions for binding are defined. Specificity of precipitation of this enzyme by the lectin was especially investigated. Thus, the possibility of binding was tested in the presence of high ionic strength, ethylene glycol, alpha-methyl mannoside, alpha-methyl glucoside and during periodate oxidation of the enzyme. Based on the interactions observed between beta-fructosidase and Con A under these conditions it is concluded that the saccharide binding site of the lectin is primarily involved with a secondary contribution from the hydrophobic site. The specificity of binding and the complete precipitation of beta-fructosidase activity by the insolubilized lectin imply that all beta-fructosidase activity measured in Raphanus sativus seedling extracts is linked to (a) glycoprotein form(s) of this enzyme.


[Possible mechanism of selective inhibition of rat liver mitochondrial monoamine oxidase by chlorgiline and deprenyl]. The inhibition of the deamination of serotonin (the main substrate of monoamine oxidase (MAO) type A) by chlorgiline and deprenyl and of beta-phenylethylamine (the main substrate of the B type MAO) by fragments of rat liver mitochondrial membrane as well as the influence of 4-ethylpyridine on this process were studied. It was shown that the MAO activity of the mitochondrial membrane fragments was highly sensitive to chlorgiline, when serotonin was used as substrate, whereas a high sensitivity toward deprenyl was observed with beta-phenylethylamine as substrate. 4-Ethylpyridine (5.10(-3) M), a competitive and reversible inhibitor of the MAO activity, inhibited deamination of serotonin and beta-phenylethylamine by 34 and 30%, respectively. In experiments with chlorgiline (the specific inhibitor of MAO type A) 4-ethylpyridine (5.10(-3) M) introduced into the samples after preincubation of mitochondria with increasing concentrations of chlorgiline (30 min, 23 degrees C) decreased the inhibition by chlorgiline of the deamination of beta-phenylethylamine, but sharply increased the inhibitory effect of chlorgiline on the oxidation of serotonin. In analogous experiments with deprenyl (the specific inhibitor of MAO type B) 4-ethylpyridine (5.10(-3) M) decreased the inhibitory effect of deprenyl not only on the deamination of serotonin (substrate of MAO A), but also on the oxidation of beta-phenylethylamine (the main substrate of MAO type B). The decrease in the inhibitory effect of deprenyl on the deamination of beta-phenylethylamine after the addition of 4-ethylpyridine may be intensified upon preincubation of deprenyl with mitochondria in the presence of 4-ethylpyridine. The data obtained demonstrate the difference in the type and mechanism of inhibition of the deamination of serotonin by chlorgiline as well as in the type and mechanism of oxidation of beta-phenylethylamine by deprenyl. The possible mechanism of selective blocking of MAO activity by chlorgiline and deprenyl was discussed in terms of our previous data on the existence in the active center of mitochondrial MAO of specific sites for substrate binding, differing in their structure-functional characteristics.


[Investigation of essential SH-groups of bacterial formate dehydrogenase]. Modification of two SH-groups in the molecule of formate dehydrogenase by dithiobisnitrobenzoate or to dacetamide results in the enzyme inactivation. Coenzymes, but not the substrate, protect the enzyme against the inactivation. NAD in the presence of potassium azide completely preserves the enzyme activity. Two SH-groups per enzyme molecule are protected from modification. The Km values for partially inactivated formate dehydrogenase remain constant for both substrates. The enzyme with modified SH-groups does not bind conezymes. The pH-dependence of the inactivation rate reveals the ionizable group with pK 9.6 (25 degrees C). The involvement of essential SH-groups in coenzyme binding is discussed.


[Mechanism of activation of acetylcholinesterase in brain tissue homogenates by detergents]. The mechanisms of activation of acetylcholinesterase (AChE) in the homogenates of rat and frog forebrains and medullae oblongatae under effects of non--ionic detergents (Triton X-100 and Tw-en 80) were studied. Titration of the active centers of enzyme by the highly selective phosphoorganic inhibitor HD-42 showed that the inhibitor-induced activation is due to the appearance of previously masked active sites of the enzyme. Activation of AChE in the homogenates of rat brain medulla oblongata was caused by lysis of the structural elements of nervous tissue which were not destroyed by homogenization. Another mechanism of AChE activation by the detergents (frog brain homogenate) is the destruction of the vesicular membrane structures present in the homogenate with AChE centers located on the inner surface of the vesicles.


[Activation of glucocorticoid cytoreceptors in rat heart]. Accumulation of 3H-dexamethasone by the nuclei in a cell-free system was studied. The increase in temperature from 0 degrees to 20 degrees C and treatment of cytosol by KCl (0.4 M) or theophylline (10mM) significantly increased the absorption the bound hormone by the nuclear fraction. Activation of the steroid-protein complex induced by temperature and addition of theophylline did not change its size. The increase in the ionic strength decreased the Stokes radius from 53 A down to 39.5 A and the sedimentation coefficient value from 7S down to 4S. It is concluded that the heart tissue cytoplasm contains a glucocorticoid receptor.


[Content of thyroglobulin polyribosomes in normal and pathological thyroid cells]. The content of individual thyreoglobulin (TG) polyribosomes in human thyroid gland was studied in healthy persons and in patients with thyroid pathology. The content of TG polyribosomes makes up to 16.2% in normal thyroid tissue and is found to decrease down to 7.8% and 7% under nodal euthyroid goiter and toxic adenoma, respectively. This content is decreased to 12.5% under diffuse toxic goiter and is intermediate between nodal and diffuse toxic goiter under mixed goiter (9.4%).


[Isolation and properties of neutral SH-dependent proteinase from bovine spleen]. A neutral SH-dependent proteinase was isolated from bovine spleen by a slight modification of the previous method (1) and its action on some natural and synthetic substrates was studied. The activity of the enzyme was increased 2000--2500-fold as compared to that of the original extract. The enzyme hydrolyzed various histones (H1, H2a, H2b, H3), casein and protamine but did not split hemoglobin, serum albumin and 14C-tryptophane-labelled total protein from chicken embryos. The enzyme possessed neither collagenolytic nor elastase activity; it did not inactivate aldolase, hexokinase, glyceraldehyde phosphate dehydrogenase and glucose-6-phosphate dehydrogenase, which makes the enzyme different from cathepsin B1 and some other previously described proteinases. The enzyme did not split BAPA, BAEE, ATEE, Boc-Ala-ONP, Leu-beta-NA and some other peptides. The molecular weight of the enzyme was found to be about 15 000.


[Affinity chromatography of subtilisin on a sorbent with epsilon-aminocapronyl-alanyl-alanyl-D-leucylamide. Detection of a serine protease with unusual properties]. A biospecific sorbent obtained by attachment of epsilon-aminocapronyl-L-alanyl-L-alanyl-D-leucylamide to CNBr-activated Sepharose 4B has been used for affinity chromatography of various samples of subtilisin BPN', e.g. subtilisin A ("Serva"), Nagarse, A-50. Two active components were isolated from subtilisin A (Serva"), the major component corresponding to subtilisin BPN' and the minor component (SII) being a serine proteinase with low molecular weight (about 10000). The molecular weight and amino acid composition of SII as well as the kinetic parameters of its action on peptide substrates (p-nitroanilides of N-benzyloxycarbonyl-Gly-Gly-Leu, -Ala-Ala-Leu, -Gly-Gly-Phe, -Ala-Ala-Phe. The low molecular weight proteinase possesses a high affinity for the leucine residue in P1 position and alanine in P2 and P3 positions. The specificity of this proteinase differs from that of the main component.


[Kinetic and allosteric properties of L-threonine-L-serine dehydratase from human liver]. It was shown that low concentrations of ATP (1..10(-4)M) and 10-fold concentrations of AMP (1.10(-3)M) at three constant L-threonine concentrations activated the L-threonine dehydratase activity of L-threonine-L-serine dehydratase from human liver, but had no effect on the L-serine dehydratase activity of this enzyme. Higher concentrations of both nucleotides inhibited the enzyme. The effects of ATP and AMP were specific. The activating and inhibiting effects of various concentrations of ATP and AMP were revealed as changes in the shapes of the curves for the initial reaction rate of the L-threonine dehydratase reaction versus initial substrate concentration. For this reaction the curves were not hyperbolic and were characterized by intermediary plateaux. ATP and AMP also influenced the maximal rate of the enzymatic reaction. Using the desensitization method it was shown that the activating effects of ATP and AMP are of allosteric nature. Thus, human liver L-threonine-L-serine dehydratase is an allosteric enzyme, for which positive allosteric effectors are low concentrations of ATP and AMP and negative allosteric effectors are high concentrations of these nucleotides. A possible mechanism of allosteric regulation of the enzyme under catalysis of the L-threonine dehydratase reaction and the lack of regulation under catalysis of the L-serine dehydratase reaction as well as specificity of the allosteric sites of this enzyme to the two nucleotides and the physiological significance of this process are discussed.


[Changes in the phospholipid content of intact mitochondria under mitochondrial swelling in hypotonic sucrose solutions]. Mitochondrial swelling in hypotonic sucrose solutions is accompanied by a decrease of the amount of phosphatidyl ethanolamines, cardiolipids and their lyso-derivatives. An addition of dicaine (inhibitor of phospholipase) to the incubation medium results in a considerable decrease of mitochondrial swelling and prevents the decay of phosphatidyl ethanolamines and cardiolipids. This effect is due to the inhibition of corresponding phospholipases. The data obtained suggest that the passive mitochondrial swelling is accompanied by activation of endogenous phospholipases and by a hydrolysis of cardiolipids, phosphatidyl ethanolamines and their lyso-derivatives.


[Interaction between immobilized antibodies and the antigen-enzyme complex]. The interaction between immobilized antibodies against human immunoglobulin G (IgG) and the immunoenzyme complex IgG-peroxidase (IgG-P) was studied. The complex was obtained by covalent binding of IgG to peroxidase modified by sodium periodate. Study of the IgG-P binding kinetics and dissociation of the antibody-(IgG-P) complex showed that the antibodies immobilized on Sepharose reversibly interacted with IgG-P, similar to the antigen-antibody reaction in solution. The efficient values of the binding constants for the antibodies binding to Sepharose covalently and through the antigen-antibody bond are (2,2+/-0,5) 10(8) M-1 and (4,2+/-0,2) 10(8) M-1, respectively. The nature of a carrier and the immobilization method used do not significantly affect the rate of the complex binding to the antibodies. The activation energy of the reaction of IgG-P binding to the antibodies immobilized on Sepharose covalently and through the antigen-antibody bond is 7,3 and 4,1 kcal/mole, respectively. A procedure of titration of immobilized antibodies active sites with the antigen-enzyme complex is discussed.


[Fusion of planar bilayer phospholipid membranes with liposomes]. Lecithine-cholesterol liposomes containing amphotericin B ionoforic marker were used to study the interaction between liposomes and planar phospholipid membranes. The liposomes were shown to increase the permeability of the planar membrane, which may be explained in terms of membrane fusion. Bivalent cations (Mg2+ and particularly Ca2+), dicetylphosphate producing negatively charged groups on the membrane surface and the n-decane suspension in water promote the fusion, whereas the increase of the cholesterol content in the liposomes prevents it.


[Fractionation of nucleosides and nucleoside-5'-mono-, di and triphosphates by thin layer chromatography in silufol]. New solvent systems--dioxane--isopropanol--water--ammonium (4:2:4:1) and dioxane--water--ammonium (6:4:1)--for rapid qualitative and quantitative estimation of nucleosides, nucleoside-5'-mono-, di- and triphosphates by thin layer chromatography is Silufol UV-254 are proposed. The Rf values for 40 ribo- and deoxyribonucleotides of these systems are given.


[Creatine kinase from muscle cell nuclei]. It has been firstly demonstrated that rat heart and skeletal muscle nuclei contain creatine dinase, one of the most important enzymes of energy metabolism. The nuclei isolated in concentrated sucrose were practically free from cytoplasm and mitochondrial fragments. Electrophoresis in acetyl cellulose revealed that the nuclear extracts from rat heart and skeletal muscles contain only one isoenzyme of creatine kinase similar in mobility to the mitochondrial isoenzyme. The magnitude of Km values for creatine kinase from the nuclei of both tissues was determined. It was shown histochemically that creatine kinase is localized inside the nuclei, predominantly in the sites of chromatin location. A possible role of the enzyme in nuclear metabolism is discussed.


[Effect of higher alcohols on the activity of biosynthetic L-threonine dehydratase from Saccharomyces carlsbergensis brewer's yeast]. The effects of low (1 . 10(-4) M) and high (1 . 10(-3) M) concentrations of n-propanol, isobutanol and isoamylols on the kinetic behaviour of "biosynthetic" L-threonine dehydratase from brewer's yeast S. carlsbergensis 776 were studied. It was concluded that these alcohols control the activity of the first enzyme of the L-threonine biosynthetic pathway.


[Effect of polyethylene glycol on association of muscle phosphorylase B]. It has been shown that a neutral polymer poly(ethyleneglycol) with molecular weight of 4000 and more shifts the equilibrium between the dimer and tetramer forms of phosphorylase B from rabbit skeletal muscles in the direction of formation of species with higher molecular weights. Poly(ethyleneglycol) with molecular weight below 600 has no effect on the association process. Phosphorylase B is precipitated in the form of crystals in the presence of poly(ethyleneglycol) mol. weight 40,000), when the concentration of the latter is higher than 50 mg/ml. AMP and sulfate ions are required for the crystallization process.


[Increases in the activity of lysosomal DNAase in mouse liver during the development of Friend's viral leukemia]. A developing Friend's viral leukemia is accompanied by a 2,0--2,5-fold increase in the activity of lysosomal DNAse (DNAse II) in mouse liver as compared to normal. The increase in activity is observed on the 10--12th day after inoculation of virus-containing material and reaches its maximum on the 20th post-inoculation day. The increase in DNAse II activity is due to activation of the lysosomal system of Kupffer's and endothelial cells of the liver. The activity of mitochondrial DNAse (DNAse I) in the livers of leukemic mice showed no deviations from the normal level. A possible role of DNAse II in the protective response of the organism is discussed.


[Inhibition of human granulocyte proteinases by a heat and acid-stable proteinase inhibitor from rabbit serum]. Several human granulocyte proteinases sensitive to the thermo- and acid-resistant proteinase inhibitor from rabbit serum (TASPI) were revealed, using TASPI-Sepharose 4B. It was found that TASPI inhibits the following human granulocyte proteinases: granules-localized kininogenase and chymotrypsin-like kininase (serine proteinases), elastase-like proteinase and benzoyl arginine ethyl ester esterase, as well as chymotrypsin-like kininase from the post-granule supernatant. These enzymes were compared to known granulocyte proteinases. Some carboxylic kininogenase sensitive to TASPI was identified in the granulocyte membrane debris fraction. The capability to inhibit neutral kininogenase suggests that TASPI is a first natural proteinase inhibitor, which can differentiate granulocyte and blood plasma kininogenases. Using trypsin-Sepharose 4B in the granulocyte post-granule supernatant, the acid-resistant trypsin and chymotrypsin inhibitor was identified. The data obtained are indicative of an antiinflammatory function of TASPI in mammals.


[Protein composition of crystals (delta-endotoxin) of different serotypes of Bac. thuringiensis]. The crystals of entomopathogenic protein from Bac. thuringiensis contain admixtures of proteinases adhering to their surfaces. A newly developed technique of protease inactivation allowed to estimate the true protein composition of the crystals of various strains of Bac. thuringiensis. It was shown that the crystals of all strains (with the exception of V and VIII) are composed of only one protein with molecular weights of 145,000, 135,000 and 130,000, depending on the strain. The crystals of serotype VIII and the majority of the V serotype strains have two proteins with molecular weights of 135,000 and 130,000. A method for estimation of the protein composition of crystal without their preliminary isolation from a crystal--spore mixture is proposed.


[Accelerated microsomal DNA synthesis under the influence of xenobiotics and chemical carcinogens]. Injection of 3,4-benz(a)pyrene, methyl nitrosourea and phenobarbital into healthy mice of the C3HA line results in a rapid, sharp increase of [14C]-thymidine incorporated into liver microsomal DNA, accompanied by a suppression of nuclear DNA synthesis. In the liver of neoplastic mice and in the ascite cells of hepatoma 22A the system of microsomal DNA synthesis was insensitive to the injection of methyl nitrosourea. Cycloheximide and puromycin, which strongly inhibited nuclear DNA synthesis, had no effect on the synthesis of microsomal DNA. Stimulation of [14C]-thymidine incorporation into microsomal DNA after injection of methyl nitrosourea and 3,4-benz(a)pyrene may be accounted for not only by an increase of the DNA reparation processes, since caffeine, the inhibitor of post-replicatory reparation of DNA, did not eliminate the induction of microsomal DNA synthesis in the liver. Hydroxyurea in combination with methyl nitrosourea and phenobarbital significantly suppressed the synthesis of nuclear DNA in the liver and did not affect the synthesis of mtDNA; the stimulating effects of these inducers on the synthesis of microsomal DNA was thereby removed. This is indicative of independence of synthesis of microsomal DNA on that of nuclear DNA and mtDNA. Different specific radioactivities of microsomal, nuclear and mtDNAs in the regenerating mouse liver on the 5th, 10th and 15th post-hepatectomy days may be due to different metabolic stability of these DNAs. A possible role of microsomal DNA as a xenobiotic system component is discussed.


[Photoinduced changes in adsorption at 800 nm related to photosystem I functioning]. The spectra and kinetics of light-induced absorbance changes in the near-infrared region of subchloroplast fragments enriched by P700 were studied. An increase in absorbancy within the region of 725--900 nm upon illumination was characterized by a maximum around 810 nm and by "shoulders" around 760 and 870 nm. Similar effects of thermal inactivation and low temperatures on the duration of dark recovery of light-induced absorbance changes at 700 nm and within the region of 725--900 nm suggest that the absorbance changes in the near-infrared region are due to photooxidation of P700. The values of P700 differential extinction coefficients at 810 nm are 8,2.10(3) M-1.cm-1 for digitonin fragments and 7,7.10(3) M-1.cm-1 for fragments prepared with the use of diethyl ester. It was shown that the value of midpoint oxidation-reduction potential measured for the absorbance changes at 810 nm (+492 mv) is higher than that measured at 700 nm (+475 mv).


[Resistance of ascitic fluid immunosuppressive factor DNA to pancreatic deoxyribonuclease]. It was found that incubation of Ehrlich tumour ascitic fluid with pancreatic DNAse does not result in a destruction of 5S DNA in the immunodepressive factor. After phenol deproteination of the ascitic fluid the resistance of this nucleic factor to DNAse is lost. It is possible that the native nucleic factor is represented by DNP and contains a protein component. During polyacrylamide gel electrophoresis the mobility of the nucleic factor labelled with [3H]-thymidine and isolated after chromatography on hydroxyapatite is found to be nearly the same as that for transferine.


[Cytochrome b556 complexes solubilized from Micrococcus lysodeikticus membranes by triton X-100]. The integral protein of cytochrome b556 after its solubilization with Triton X-100 from M. lysodeikticus membranes was studied. The cytochrome was found in complexes differing in charge and size during preparative gel electrophoresis and centrifugation in a sucrose concentration gradient. Cytochrome b556, being in complexes, retains its ability to be reduced by NADH dehydrogenase. The electron micrographs of the membranes after solubilization by Triton X-100 demonstrated the maintenance of the membrane structure. It is concluded that native protein complexes marked with cytochrome b556 are extracted from the membranes under their solubilization.


[Accessibility of microsomal membrane proteins for protease K]. The effect of protease K on the microsomal membrane proteins was studied. It was shown that treatment of the microsomal membranes by low concentrations of protease did not remove more than 35% of total membrane proteins. Treatment by higher protease concentrations removed about 50% of the proteins. The residual protein is accessible to protease after treatment of the membranes by phospholipase A2. A simultaneous treatment of the microsomal membrane by protease and phospholipase removed up to 80% of the membrane proteins. In this way about 30% of microsomal membrane proteins are protected by the phospholipid against the action of protease K.


Evidence that the renal response to volume expansion involves a blood-borne factor. The effect of blood volume expansion in immature rats by blood from infants (J to J expansion) and mature animals (A to J) has been studied. A to J expansion results in an increased renal response to expansion which is greater than J to J, but not as great as when mature animals are expanded with blood from other matures (A to A) or pooled blood from infants (J to A). A to A and J to A expansions show no significant differences in renal responsiveness. The lack of an immature response is not due to differences in animal hydration since 2.5% volume expansion is on the flat part of dose response curve. Part of the scatter of the adult response is related to absolute levels of GFR which might indicate the existence of a filterable natriuretic factor or, alternatively, a dependence of renal responsiveness on filtered load. These results are interpreted to indicate that mature rats contain a natriuretic factor or an inhibitor of an antinatriuretic factor which is blood borne and is probably secreted in blood volume expanded rats.


Pyrimidine metabolism in erythrocytes of the newborn. Activities of orotate phosphoribosyltransferase and orotidine-5'-phosphate decarboxylase were found to be significantly higher in erythrocytes from newborn infants than in erythrocytes from adults, and approximated those observed in patients with deficiency of hypoxanthine-guanine phosphoribosyltransferase. Enzyme activities were increased to a varying extent in patients with reticulocytosis. The results are discussed in relation to red cell age and stabilization of the enzymes by phosphoribosylpyrophosphate. Pyrimidine-5'-nucleotidase was assayed by a new radiochemical method involving thin-layer chromatography for separation of product from substrate. Enzyme activity was higher with orotidine monophosphate than with uridine monophosphate. The activity of this enzyme was similar in erythrocyte of newborns and adults.


The effects of theophylline on renal function in the premature newborn. The effects of aminophylline on renal function in 10 premature infants with idiopathic apnea are evaluated. The percent increases in creatinine clearance (128 +/- 339%, mean +/- SD) and sodium clearance (196 +/- 304%, mean +/- SD) are variable while the percent increase in fractional sodium excretion (69 +/- 109%, mean +/- SD) is significant. This effect is postulated to be at the proximal tubule and may be modified by the effects of postnatal age and infusion of albumin. Gestational age, birth weight, heart disease, water and sodium intake and ventilatory support did not appear to influence the results. Hyponatremia is a potential consequence of theophylline therapy for apnea.


Response of the organs of rabbits to feeding during the first days after birth. An experiment described previously showed a large increase in weight and protein of the intestinal mucosa of suckling piglets during the first 24 h after birth. This did not take place in piglets that were starved. The results might have been partly due to the inclusion of protein molecules in the mucosa in process of absorption. Rabbits do not absorb large quantities of protein after birth, and the experiment has now been repeated on them. The gastrointestinal tract of suckled rabbits also grew rapidly in the first 24 h, but again not in those that were given only water, which is in line with the suggestion that colostrum contains a factor which stimulates the growth of the gastrointestinal tract. The brain gained weight in the suckled animals, due to incorporation of lipid and protein. It gained weight too in the starving rabbits, demonstrating its high priority for nutrients at a time when its growth velocity is at its peak.


Comparison of cardiovascular reflexes of the newborn and adult opossum. Neural control of the cardiovascular system was compared in the newborn and adult opossum by measuring changes in blood pressure and heart rate following carotid arterial occlusion and vagal stimulation. The percent change in blood pressure of the newborn was not significantly different from that of the adult following these procedures. This would indicate that even though the newborn opossum is incompletely developed for some time after birth, its neural development was adequate for control of the cardiovascular system.


Glucose tolerance tests in women with small-for-date fetuses and newborns. Peroral glucose tolerance tests were performed in women with small-for-date fetuses and in controls with healthy fetuses in the 38th week of pregnancy, 2 days and 6 weeks after delivery. 2 h after the load of 50 g of glucose, the blood glucose level remained significantly higher in pregnant women with small-for-date fetuses. The other parameters followed did not exhibit any difference from the control group. Since this deviation disappeared very rapidly after delivery it may be supposed that it is caused by hormonal and other influences of the atypical conceptus and not by a primary derangement of maternal metabolism or by a disparate responsiveness of the maternal organism to pregnancy.


Underlying disorders responsible for the neonatal deaths associated with low Apgar Scores. Data from a large study were used to determine the frequency of fatal disorders associated with low Apgar scores. 5-min scores had the best correlation with mortality rates. Death rates were more than ten times greater with abnormal than with normal 5-min scores. This difference was only 3-fold for 1-min values. Amniotic fluid infections were responsible for nearly half of the deaths in preterm and 24% of the deaths in term neonates with 5-min Apgar scores 0--6. The respective values for disorders that cause antenatal hypoxia were 25 and 24% and for major congenital anomalies, 7 and 28%.


Effect of hormones on the development of creatine kinase activity in rat skeletal muscle. Various approaches have been used in order to determine whether or not a certain hormone is a stimulus for the development of the muscle-specific enzyme, creatine kinase. Both thyroxine and glucocorticoids can be considered as naturally occurring stimuli for the synthesis of creatine kinase. The maximum increase of creatine kinase activity after stimulation by glucocorticoids (about 25%) occurs between 5 and 7 days after birth. A single injection of thyroxine has virtually no effect during this period. However, when a pretreatment with thyroxine is given, cortisone acetate administration increases creatine kinase activity to about 155%. The effect of cortisone acetate is due to de novo synthesis of creatine kinase. The augmentation of the effect of cortisone acetate by thyroxine is dependent on DNA synthesis. Thyroxine administration apparently causes the formation of more competent muscle cells. The effects of both hormones are age-dependent. Thyroxine and cortisone acetate administration to fetuses can prematurely evoke to MM isoenzyme of creatine kinase. Both hormones probably play a role in the activation of the M gene during embryonic development. Sex hormones are able to influence neither creatine kinase activity nor muscle growth. However, castration of male rats immediately after birth causes an impairment of growth at older ages. The androgen production by the testes immediately after birth seems to be of main importance for body growth development. It can be concluded from these results that creatine kinase in muscle is under multiple hormonal control, just as is observed for a number of enzymes in other tissues.


Fetal thyrotoxicosis in utero.

Fetal thyrotoxicosis in utero. A case of fetal thyrotoxicosis in utero in a boy with familial predisposition to thyrotoxicosis is reported. At 26 weeks of gestation fetal hyperkinesia and fetal tachycardia developed. This was preceded by a significant pathologic increase in long-acting thyroid stimulator (LATS) in the mother. The fetal hyperkinesia and tachycardia were considered to be signs of fetal thyrotoxicosis, possibly induced by placentally transferred LATS. The fetal thyrotoxicosis responded well to propylthiouracil given to the mother. After birth the boy developed slight signs of neonatal thyrotoxicosis although his serum thyroxine values increased analogous to those of his elder sister, who had presented classical neonatal thyrotoxicosis.


Postnatal development of renal function in piglets: glomerular filtration rate, clearance of PAH and PAH extraction. Glomerular filtration rate (GFR), estimated as clearance of inulin, and clearance of p-aminohippuric acid (CPAH) were measured in 32 unanaesthetized piglets 1--62 days of age. During this period of time, GFR increased from 0.27 to 0.59 ml/min/g kidney and CPAH increased from 1.02 to 1.72 ml/min/g kidney. At 8 weeks of age, GFR and CPAH equaled adult values. In addition, renal PAH extraction (EPAH) was estimated in 12 anaesthetized piglets aged 1--79 days. EPAH increased from 0.75 at birth to 0.86 (adult value) at 3 weeks of age. The result shows a postnatal increase in renal functions in piglets, but the development from birth to adult level was less pronounced than seen in other animal species.


Secretory proteins in the perfused human placenta. A relatively simple perfusion technique of human placenta has been applied to the study of secretory proteins. Preferential secretion into the maternal circulation of human chorionic gonadotropin (HCG), human chorionic somatomammotropin (HCS), follicle-stimulating hormone (FSH), and placental alkaline phosphatase has been demonstrated, contrasting with the bidirectional secretion of progesterone. Evidence is presented for the net synthesis of HCS during perfusion. The technique offers advantages in the study of synthesis and secretion of placental materials.


The response of adult rats weaned prematurely and normally to starvation. Male rats were weaned normally (NW; day 30 after birth) or prematurely (PW; day 18) to a Purina Chow diet. Serum cholesterol levels and the activities of some enzymes of fatty acid and glucose metabolism were determined when the animals were 6 and 10 months old and, in the older group, also after 2 days of starvation. Blood cholesterol levels rose with age and at 10 months were higher in PW than NW rats. This difference disappeared after starvation. Hepatic pyruvate kinase (PK) activity was the same in fed NW and PW animals but was significantly higher in starved PW than NW rats. Hepatic phosphoenolpyruvate carboxykinase (PEPcK) activity was lower in NW than in PW rats, but this difference disappeared on starvation. In white fat, starvation caused a fall in PEPcK activity in both groups. In general, the effect of starvation did not accentuate the differences between the two groups. However, PEPcK activity in white fat increased with age about fourfold.


Synthesis of arachidonic acid in the human placenta in vitro. The syntheses of arachidonic acid and total fatty acids were measured in human placentas at the end of the first trimester and at term using 14C-acetate in in vitro incorporation experiments. The rates of arachidonic acid synthesis were determined to be 0.70 (first trimester) and 0.64 (term) mumol/h/100 g of placental tissue. The calculated rates of total fatty acid synthesis amount to 0.5 (first trimester) and 0.6 (term) mumol palmitate-equivalents/h/100 g. The results suggest that the human placenta seems to be not dependent on maternal arachidonic acid. Near term the placenta even could be source of arachidonic acid.


Enzyme immobilization by radiation-induced polymerization of hydrophobic glass-forming monomers at low temperatures. Enzyme immobilization was studied by means of radiation-induced polymerization of hydrophobic glass-forming monomers at low temperatures. The polymerized hydrophobic composite was generally obtained in microspheric form. Enzymatic activity showed little decrease with repeated use in these systems. The particle size of the microsphere increased with increasing monomer concentration, and activity yield had a maximum at an optimum monomer concentration. Immobilization by copolymerization of hydrophilic and hydrophobic comonomers was also investigated and a maximum activity yield was found at a certain monomer concentration. A model scheme for immobilization at low temperatures was proposed and discussed.


[Reactions of neurons in the dental projection area of the rabbit sensomotor cortex to photic, acoustic and painful stimulation of the dental pulp]. In experiments on unrestrained rabbits interactions of sound (tone, click), light and pain excitation occurring during stimulation of the dental pulp in the neurons of the cortical sensomotor zone, in the area of representation of the dental afferents were studied by the microelectrode method. It was shown that bi- and polysensor convergence of excitation is realized in the cells of this area. It is suggested that convergence of excitation underlies the mechanisms of formation of the integral systemic pain reaction during stimulation of the dental receptors.


[Reaction of bone marrow colony-forming cells in irradiated mice to phlogogenic factors]. The experiments on irradiated mice (600 and 800 r) demonstrated that under the influence of flogogenic factors the quantity of colonies in the spleen increases and their morphological structures change. It is suggested that under the action of the damaging agent the "hypothetic factor" which causes the pointed changes, is formed in the skin.


[Effect of vagotomy on permeability processes in the structural components of rat liver]. The method of intravital fluorescence microscopy was used to study permeability by sodium fluoresceine of the structural components of the rat liver 7,21 and 60 days after bilateral subphrenic vagotomy. It was found that vagotomy resulted in a permeability rise both of the liver microvessels and hepatocyte plasma membranes. Later the temporal indices return to the initial levels.


[Hemodynamic component in cerebral compensatory processes following unilateral exclusion of the somatosensory cortex]. In experiments on anesthetised and awake cats the dynamics of the cerebral blood flow was studied by the thermoelectric method in one hemisphere in experimental lesion of the somatosensory zone of the opposite one. Temporary exclusion of the cortical area by cold produced evident hemodynamic changes, i. e. a two-phase vasoreaction and an initial blood flow decrease followed by a prolonged increase of blood supply, in the other hemisphere. Analogous vasoreactions were seen on unilateral extirpation of the cortical layer of the somatosensory zone, as well. Such vasoreactions indicate enhanced activity of the cortical structures in the intact hemisphere and may be considered as a compensatory reaction to the local lesion of certain cortical areas.


[Mechanism of the antiexudative action of heparin]. The skin inflammation was induced by xylol application in experiments on rats. Exogenous and endogenous hyperheparinemia was found not to influence the dynamics of microcirculatory changes in the inflammatory area at the onset of its development, vascular permeability being significantly decreased. It is suggested that decreased vascular permeability plays an important role in the mechanism of antiexudative heparin action.


[Monosynaptic reflexes of the cat spinal cord during the development of insulin hypoglycemia]. Insulin-induced hypoglycemia caused depression of rhythmic monosynaptic EPSP motoneurons of the lumbar cord in acute experiments on narcotized and spinal cats. It was demonstrated that growing depression of monosynaptic transmission was associated with the exhaustion of mediator operative fraction and not with any pre- or postsynaptic delay or inhibition over a period of initial hypoglycemia when the sugar content in the blood fell to the level of 50--60 mg%. The function disturbance of postsynaptic formations of monosynaptic reflex arc of spinal cord occured in more advanced hypoglycemia.


[Multiple forms of DNA-ase activity in the nuclei of spleen lymphocytes]. The nuclei of spleen lymphocytes showed nuclease activity becoming manifest under conditions optimal for different types of DNA-ase (DNA-ase I, DNA-ase II, micrococcal nuclease and Ca, Mg-dependent endonuclease). No diversity of nuclease activity was found in the liver or kidney nuclei. A high nuclease activity in the lymphocyte nuclei provides for a deeper endonucleolysis of the lymphocyte chromatin as compared to that in the liver nuclei. The variety of nucleic activity and more advanced chromatin endonucleolysis in the spleen lymphocyte nuclei may be associated with rapid cell renewal of the lymphocyte pool in lymphoid organs and with necessity for autolysis of degraded lymphocyte genome. It may also ensure the somatomutagenic mechanism of diverse V-genes and of V- and C-gene combination.


[Relation of the ultrastructural organization of mouse mammary gland cancer to its ability to metastasize]. A quantitative ultrastructural investigation of cancer in mice mammary glands and of its metastases to the lungs was carried out. It was established that in tumors showing no metastatic spreading in experiment the area of membrane surface of the endoplasmic reticulum and the number of bound ribosomes are greater than those in tumor spreading metastases. At the same time the number of ribosomes organized into polysomes is higher in the metastasized tumors. The comparison of the tumors with their metastases revealed differences in the structure of the mitochondrial apparatus: the surface area of cristae is larger in the metastatic foci. The evidence obtained shows that tumors spreading metastases have a lower level of cellular differentiation. The primary and metastatic foci do not exhibit any difference in the level of differentiation.


[Radiosensitivity of colony-forming units of dog bone marrow in agar cultures]. Radiosensitivity of the bone-marrow colony-forming cells was determined by a modified method of hemopoietic cells cloning in vivo in semihard agar gel in diffusion chambers. Do for the commited precursor cells of granulopoiesis (CFUc) was 144 +/- 14.8 rad (n = 0.8), and Do for the precursor cells forming "stellate" colonies of fibroblast-like cells (PFUf) was 468 +/- 35.8 rad (n == 0.9). A conclusion was drawn that PFUf were referred to the class of stromal precursors of the hemopoietic organs. This system can be applied for a simultaneous study of the hemopoietic and stromal precursor cells in dogs.


[Effect of tissue macrophage destruction products on hematopoietic stem cells]. Products of mouse peritoneal macrophage destruction (PMD) obtained by aseptic freezing-thawing of the cells, repeated thrice, were found to elicit in syngeneic mice injected with PMD intraperitoneally an increase of CFUs count in the hemopoietic bone marrow tissue and the spleen, as demonstrated by the Till and McCullooch technique. This proved to be a true increase since the transplatned stem cell fraction sorbed by the recipient's spleen was relatively lower in donor mice given PMD than in the control. Although PMD caused an increase of both erythropoietic (E) and granulocytopoietic-monocytic (G) colonies number, the E/G ratio was decreased; one of the mechanisms of the described effect could be the influence of PMD on the hemopoiesis-inducing microenvironment, as the same effects were obtained in mice injected repeatedly with PMD prior to the transplantation of bone marrow tissue of normal donors. Other possible mechanisms of these effects were analyzed, with consideration to the fact that in experiments with preincubation of bone marrow tissue with PMD prior to injection to the lethally irradiated mice no direct stimulating influence of PMD on the stem cell could be revealed.


[Binuclear cells in rat liver during repair regeneration of the organ]. At early stages after partial hepatectomy (17 hours after the operation) binuclear cells become involved in proliferation in much lesser numbers, and 37 and 53 hours after the operation--in much greater numbers relative to their part in the population. New formation of binuclear cells (the presence of labeled binuclear cells 20 hours after the thymidine H3 administration) was the most intensive at the early regeneration stages (16--36 hours after the operation), when about 20% of mitoses are acytokinetic and lead to the formation of binuclear cells. At later periods only 8% of mitoses result in formation of binuclear cells.


[Neuroblast differentiation and migration in the developing human spinal cord in the 1st half of prenatal ontogenesis]. The processes of neuroblasts differentiation and migration in the developing human spinal cord in the first half of antenatal ontogenesis were studied by the Golgi method. The neuron development was traced from the neuroepithelial matrix cells to the maturing neurons. A possible role of a special neuroblast outgrowth as a channel for its nucleus migration to the definite typological position of the mature neuron is suggested.


[Microcirculatory bed of serous membranes in rats with spontaneous genetic hypertension]. The microvasculature (MV) of serous membranes was compared in rats with spontaneous genetic hypertension (SHR) and in normotensive Wistar rats. The study showed that in hypertension MV lesions had a systemic distribution, as structural changes were present in every MV component (arterioles, precapillaries, capillaries, postcapillaries, venules, lymphatic capillaries, and postcapillaries, nerve fibers); these lesions were generalized, as similar alterations could be found in all serous membranes studied. A close resemblance observed between MV of serous membranes in SHR and in patients who died of hypertensive disease confirms the concept suggesting the existence of MV changes which were relatively specific for hypertension, along with those of the nonspecific nature. Specificity of the hypertensive process is manifested in severe vascular lesions of a peculiar type, while the nonspecific phenomena are represented by a combination of intravascular, perivascular, and minimal vascular alterations represented by a universal MV response to various stresses.


[Ultrastructure of endocrine cells in the gastric fundal glands at different seasons of the year]. Endocrine cells of gastric glands of Citellus erythrogenus Brandt were studied during various seasons of the year by electron microscopy. ECL, EC, D and D1 cells having different structure of granules were detected. The slightly changed, weakly functioning cells as well as the cells of different alteration degree (up to destructing) were found in hibernating rodents. The presence of actively functioning EC-cells over this period confirms an opinion concerning the influence of peripheral serotonin on the hibernation mechanism. On the 3d--4th day of awakening pronounced activation of endocrine cells, their rejuvenation and normalization of cell ultrastructure, completed two weeks after awakening, were noted.


[Heterogeneity in the distribution of cytochrome P-450 in the liver lobule revealed on exposure to carbon tetrachloride]. A comparative study was made of cytochrome P-450 content and the histological pattern of the development and elimination of necrotic foci arising in the liver of CBA mice after inhalation of CCl4 vapour. Two hours after the inhalation the content of cytochrome P-450 was reduced by a factor of 1.7, and in 17, 24, and 48 hours--by a factor of 6. The necrotized area was about 40% of the total liver lobe area. It is supposed that the selective (CCl4) damage of the central lobe hepatocytes was related to the marked differences between the cytochrome P-450 content in different areas of the lobe.


[Ultrastructural changes in loose connective tissue histiocytes in dehydration and starvation]. Changes in the parameters of the volumetric fractions of the main cytoplasmic organellae were studied in the subcutaneous connective of albino rats subjected to experimental dehydration and starvation. There were some common features in the histiocytes reaction under these conditions, i. e. hypertrophy of the lysosomal apparatus and cell "infiltration" with lipids. At the same time the following differences are emphasized: dehydration caused an increase of the volumetric mitochondrial fractions and of the rough endoplasmic reticulum, and starvation of the phagosomal fraction.


[Change in the permeability of vessels in the microcirculatory bed of skeletal muscles in conditions of working hyperemia]. Permeability of m. quadriceps femoris and m. gastrocnemius mimicrocirculatory bed of albino rats was studied by fluorescent biomicroscopy at rest and under work hyperemia. Fluorescein-labeled bovine globulin (FBG) was used as an indicator of permeability alteration. Quantitative fluorescent analysis was carried out on a microspectrofluorimeter. In work hypermia the FBG concentration in the muscle exceeded such at rest by 40--45%; this evidenced an increased transendothelial transport. The results of the experiments on the measurement of FBG concentration about a single capillary suggested that the microcirculatory bed permeability increased under work hyperemia.


Interference of levamisole with inhibition of E-rosette formation by Hodgkin's disease and systemic lupus erythematosus cytotoxic sera. A new system has been used to test the influence of levamisole on T-cell function. Evidence has been produced that prior exposure to the drug "protects" normal human peripheral blood lymphocytes from the inhibition that cytotoxic sera from patients with Hodgkin's disease and systemic lupus erythematosus exhibit on their E-rosette-forming capacity. Also, damage of this T-cell function already induced by Hodgkin's sera may be partially corrected.


Hematin administration to an adult with lead intoxication. Lead poisoning and acute intermittent porphyria (AIP) may exhibit similar neurologic manifestations, and they have in common elevated excretion of urinary aminolevulinic acid (ALA). Despite their similarities, the possible pathophysiologic connection between AIP and lead poisoning in not known. Because intravenous hematin administration has produced biochemical improvement in AIP, a hematin trial in lead intoxication was of interest with respect to some of the heme metabolism abnormalities observed in the condition. Significant diminution of urinary ALA and coproporphyrin excretion occurred in association with intravenous hematin administration.


Treatment of refractory splenomegaly in myeloproliferative disease by splenic artery infusion. Five patients in the blastic phase of chronic granulocytic leukemia with massive splenomegaly were treated by intraarterial splenic artery infusion of cytosine arabinoside. All patients had massive splenomegaly associated with pain and/or hypersplenism and were refractory to previous therapy. All 5 patients demonstrated responses to treatment, with reduction in spleen size as well as symptomatic relief. Systemic toxicity was minimal in 4 of the 5 patients.


Identification of megakaryocytes, macrophages, and eosinophils in colonies of human bone marrow containing neurtophilic granulocytes and erythroblasts. Pluripotent hemopoietic progenitors in human bone marrow can be identified by their ability to give rise in culture to colonies that contain more than one lineage of hemopoietic differentiation. Growth of these mixed colonies is supported by media conditioned by leukocytes in the presence of phytohemagglutinin (PHA-LCM) and erythropoietin. They can be readily recognized by direct microscopic observation because of their composition of colorless cells and cells with a red appearance typical for hemoglobin. Seventy-three individual mixed colonies from 6 individuals were prepared by cytocentrifugation for further cytological examination. In addition to neutrophilic granulocytes and erythroblasts, megakaryocytes were present in 16 of the 73 colonies, as identified by positive reaction for acid phosphatase. Macrophages were found in 24 and eosinophils in 6 of the 73 colonies.


Comparison of sizes and shapes of tumor cells in plasma cell leukemia and plasma cell myeloma. Thirteen cases of plasma cell leukemia and 13 cases of nonleukemia plasma cell myeloma were compared with respect to the sizes and shapes of tumor cells in marrow smears. It was demonstrated that the leukemia cells were elongated or ovoid and significantly smaller in size, whereas the myeloma cells were generally more nearly round and larger.


Arsenic-induced bone marrow toxicity: ultrastructural and electron-probe analysis. A patient with severe arsenic poisoning that resulted in marked peripheral blood and bone marrow abnormalities, including megaloblastic erythropoiesis experienced many of the previously reported hematologic complications of arsenic poisoning: leukopenia, granulocytopenia, absolute eosinophilia, and profound anemia. In this study we report an ultrastructural and electron-probe analysis of the bone marrow. Although megaloblastic anemia associated with arsenic poisoning has been described rarely, the presence of arsenic in the local bone marrow milieu has not been demonstrated previously. The ultrastructural features of arsenic-induced bone marrow toxicity are similar to those described in other dyserythropoietic states and include marked nuclear aberrations involving shape, chromatin distribution, and nuclear envelope. Using the technique of energy-dispersive x-ray analysis (electron probe) we demonstrated arsenic in bone marrow spicules; this supports the contention that arsenic can cause megaloblastic anemia. We suggest that this technique may be a useful tool in further studies that attempt to explore the mechanism of arsenic-induced hematologic toxicity. Finally, we suggest that arsenic has a direct toxic effect on DNA synthesis that results in marked disturbances of nuclear division. We recommend that the most appropriate screening procedure to evaluate possible arsenic poisoning is tissue arsenic measurements (hair and nails) rather than 24-hr urinary measurements.


Protease activity in the human erythrocyte: localization to the cell membrane. Proteolytic activity in the mature human erythrocyte was localized to the cell membrane. This activity, which could not be ascribed to contaminating leukocytes in the suspension, was totally absent from the soluble portion of the cell and was more active against hemoglobin subunits than against tetrameric hemoglobin molecules. Pulse-chase experiments confirmed that the membrane proteolytic activity was more active in degrading beta chains that alpha chains. The activity could be extracted from erythrocyte cell membranes, but not from membrane-free hemolysate, by exposure to 0.75-M KSCN. The activity of the protease was dependent on time and temperature and did not require ATP or an energy-generating system for activity.


Granulocyte function during lithium therapy. Random migration, chemotaxis, phagocytosis, and bactericidal ability of neutrophils from 5 patients receiving lithium carbonate were compared with those of neutrophils from healthy donors. These cells functioned normally in all respects. Neither sera from patients receiving lithium carbonate nor the addition of lithium chloride to control cells in vitro significantly altered their functional capacity. These findings suggest that neutrophil function in patients receiving lithium therapy is preserved, and they support the potential utility of this drug as a leukopoietic agent in neutropenic states.