Polyol permeability of the human red cell. Interpretation of glucose transport in terms of a pore. The kinetic equations describing transport through a pore that has a binding site and that undergoes a conformational change are identical to those of a carrier model. Therefore, in order to distinguish between the two models it is necessary to test specific predictions based on detailed mechanistic models. A pore model is described in which the substrate (glucose) is able to reach the single binding site only from the outside when the pore is in conformation I and only from the inside when it is conformation II. On the basis of this model it is predicted that solutes which do not have any specific affinity for the binding site should still have a finite permeability via the glucose transport system if they are the same size or smaller than glucose. This permeability should be proportional to the volume of distribution of the solute in the pore and should therefore decrease with increasing molecular size. A geometric pore volume can be estimated from this size dependence. In order to test these predictions, the glucose-dependent permeability of a series of 4-carbon (erythritol), 5-carbon (D-arabitol, L-arabitol and xylitol) and 6-carbon (D-mannitol, D-sorbitol and myo-inositol) polyols was measured. The permeability of all the polyols is decreased by the presence of glucose and the KI of this "inhibitable" component is similar to that D-sorbose, suggesting that this component is associated with the glucose transport system. Since these observations could be explained entirely in terms of a specific affinity for a carrier binding site, they do not exclude a carrier mechanism. However, as predicted for the pore model, this "inhibitable" permeability decreased with increasing molecular size and the calculated geometric pore volume was of a size that would be expected for a cell membrane pore.


Molecular orientation in the stacked dimer form of 5"AMP in aqueous solution. A study by the NMR-desert method. Molecular orientation of 5"-AMP in its stacked dimeric form in neutral aqueous solutions has been investigated at room temperature through the NMR-DESERT method proposed earlier by Akasaka et al. (J. Magn. Resonance, (1975) 18, 328-343). The effect of deuterium substitution of H8 of the adenine ring on the relaxation rate of H2 has become appreciable with increasing concentration of 5"-AMP, which should be attributed to the intermolecular H2-H8 interaction between adjacent adenine rings in the stacked dimer of 5"-AMP. The reciprocal sixth-power-averaged distance between H8 and H2 of the adjacent adenine rings in the stacked dimeric form obtained from the differential relaxation rate for H2 has been found to be almost constant (3.6 +/- 0.2 A S.D.) in the whole concentration range studied (0.1--1.0 M). The result has presented a direct proof of the existence of trans-stacking with a relatively large proportion (more than 60%) in the stacked dimeric form of 5"-AMP.


Identification of human DNA sequences complementary to chromosomal RNA with an improved RNA/DNA gradient hybridization technique. Native DNA components in the human genome were identified with an improved RNA/DNA gradient hybridization technique. 3H-Labelled complementary RNA transcribed from total human DNA was hybridized to homologous DNA which had been mildly sheared to generate single-stranded ends. Unhybridized RNA was eliminated from the reaction mixture by column chromatography before the hybrids were subjected to CsCl gradient centrifugation. Nine radioactive peaks representing RNA/DNA hybrids were reproducibly found at buoyant densities of 1.687, 1.693, 1.696, 1.699, 1.702, 1.705, 1.708, 1.711 and 1.715 g/cm3. The technique was also utilized to hybridize I125-labelled human chromosomal RNA to DNA. Three distinct radioactive peaks were found at the heavy buoyant densities of 1.702, 1.705, and 1.708 g/cm3, suggesting a differential enrichment of DNA components with sequences complementary to chromosomal RNA.


RNA synthesis in isolated nuclei of Xenopus laevis emproyos. Nuclei were isolated from tailbud embryos of Xenopus laevis and their RNA synthetic activity was studied. The activity was sensitive to actinomycin D, and required the presence of all four ribonucleotide triphosphates and a divalent cation (Mg2+ or Mn2+). The effect of the divalent cation varied depending on the presence of 0.4 M KCl: in its absence more RNA was synthesized with Mg2+ than with Mn2+, but in its presence the situation was reversed. About 50% of the RNA synthesized was sensitive to the presence of alpha-amanitin. Polyacrylamide gel electrophoresis of the labeled RNA revealed that the RNA synthesized had a very heterogeneous size distribution ranging from 40 to 4 S, with a broad peak at around 28--18 S. The RNA which was distributed at around 28--18 S and 4 S was resistant to the presence of a low dose of alpha-amanitin, suggesting its ribosomal and soluble RNA nature. The RNA which was sensitive to this drug and hence may be assumed to be messenger RNA was distributed mainly between 18 and 4 S. From these results it appears that the isolated embryonic nuclei retain their activity to synthesize all of the major classes of RNA.


Isolation and characterization of 32P-labeled mitochondrial and cytosol ribosomal RNA from germinating wheat embryos. With the aim of preparing highly labeled material, the incorporation of [32P]-orthophosphate into mitochondral and cytosol ribosomal RNA was examined in germinating wheat embryos. Nucleic acids were extracted from mitochondria and from post-mitochondrial supernatant (cytosol) prepared from homogenates of viable embryos (8g) imbibed for 24h in a medium containing [32P]orthophosphate (100mCi). High-molecular-weight ribosomal RNA was selectively precipitated in the presence of 3M NaCl and was further resolved on sucrose density gradients and polyacrylamide gels. Both the mitochondrial and cytosol NaCl-insoluble RNA fractions were found to contain two major radioactive components, corresponding to the large (26S) and small (18S)rRNA species. On non-denaturing gels, these species had apparent molecular weights of 1.3 and 0.67 million daltons (cytosol) and 1.3 and 0.75 million daltons (mitochondrial). The individual, purified [32P]rRNA components (isolated from sucrose gradients) had specific activities of 2--3-10(6) cpm/A260 unit, and were suitable for analysis of nucleotide composition and sequence. By hydrolyzing the individual [32P]rRNA specimens with purified snake venom phosphodiesterase and resolving the products by two-dimensional paper chromatography, it was possible to determine the specific activities (cpm/micronmol) of the four major 5'-nucleotide constituents. The results indicated that there had been no differential 32P-labeling of the nuclear and mitochondrial pools of ribonucleoside 5'-triphosphates (rNTP) during the 24 h imbibition period; however, as previously observed in this system (Lau, R.Y., Kennedy, T.D. and Lane, B.G. (1974) Can. J. Biochem. 52, 1110--1123), there had been unequal 32P-labeling of the individual rNTPs in both the mitochondria and nucleus. The relative specific activities of the 5'-nucleotide constituents of the mitochondrial and cytosol rRNA species were essentially the same, and in the order pA congruent to pU greater than pG greater than pC. By making suitable corrections for these differences in specific activity, the nucleotide composition of each of the [32P]rRNA specimens could be calculated...


The action of N-hydroxy-2-acetylaminofluorene on the synthesis of ribosomal and poly (A)-RNA in normal and regenerating liver. Polyribosomal RNA prepared from normal and regenerating liver was chromatographed on poly(U)-Sepharose to obtain rRNA and poly(A)-RNA. Under the conditions employed for labeling the RNA with [5-3H]orotic acid, poly (A)-RNA from regenerating liver represented 1--3% of the total RNA content, and 14--18% of the total radioactivity in polyribosomal RNA at varying times after partial hepatectomy. The specific activity of poly (A)-RNA was elevated by 50% and 30% only at 2 h and 6 h after partial hepatectomy, respectively. Ribosomal RNA synthesis increased 2.5--4 fold at 2--20 h after operation. Treatment of normal or partially hepatectomized rats with N-hydroxy-2-acetylaminofluorene showed a differential dose-dependent effect on rRNA and poly (A)-RNA synthesis with rRNA synthesis being more sensitive to the inhibitory effect of the carcinogen. No change in the poly(A) content was apparent as a result of N-hydroxy-2-acetylaminofluorene treatment.


Genetic effects of photoadducts and photocross-links in the DNA of phage lambda exposed to 360 nm light and tri-methylpsoralen or khellin. The furocoumarin, 4,5',8-trimethylpsoralen, sensitizes cells and viruses to 360 nm light, producing cross-links and monoadducts in their DNA. The furanochromone khellin is a less effective sensitizing agent than psoralen, but has been found to induce cross-links and adducts in DNA also. The number of cross-links increases as the square of the time of exposure to light. We found that greater fluences were required for khellin than for psoralen, possibly because of the less favorable angle of the distal unsaturated bonds for corss-linking pyrimidines in adjacent base pairs. By adjusting the time of exposure to 360 nm light, lambda phages were damaged with [3H]psoralen and [3H]khellin so as to produce equal numbers of cross-links. These exposures were found to produce 8-times more [3H]khellin than [3H]psoralen adducts in the DNA of the phages. Similar exposures were made with nonradioactive photosensitizers to determine the effectiveness of lambda phages carrying cross-links and monoadducts in producing genetic recombinants. Lambda phage-prophage genetic corsses were performed with psoralen and khellin-damaged phages under repressed conditions in which replication of the damaged DNA was blocked. It was estimated from the results that cross-links were about 20-times more effective than monoadducts for inducing recombination under repressed conditions. In tests on the survival of plaque forming ability on wild type bacteria, it was estimated that cross-links were about 15-times more effective than the adducts. The results support the conclusion that, in homoimmune crosses with psoralen-damaged lambda phages infecting wild type lysogens, more than three-quarters of the induced recombination can be attributed to cross-links rather than to monoadducts.


Mitochondrial DNA polymerase from rat liver. A DNA-dependent DNA polymerase from rat liver mitochondria was partially purified and characterized. Mitochondrial DNA polymerase has been found to be quite different from other DNA-dependent DNA polymerases alpha and beta present in the rat liver in the following points: elution patterns in a DEAE-cellulose column chromatography, sedimentation coefficients determined by the glycerol gradient centrifugation in the presence of high salt, and sensitivities to N-ethylmaleimide, ethidium bromide and KCl.


Structure of single-stranded virus RNA in situ. II. Optical activity of five tobacco mosaic-like viruses and their components. ORD and CD spectra of some TM-like viruses and their coat proteins were measured to study a possible role of tryptophan residues in RNA-protein interactions in these viruses. Five viruses of this group, differing in tryptophan content of their coat proteins, were used: v-TM virus (3 tryptophan residues per protein subunit), strains HR and U2 (2 tryptophan residues per subunit), dolihos enation mosaic virus and cucumber virus 4(1 tryptophan residue per subunit). The viruses differ significantly in their ORD and CD spectra and some correlation between these spectra and tryptophan content of coat proteins seems to exist. But an analysis of "intravirus RNA" CD spectra, obtained by subtraction of CD spectra of virus -like protein assemblies from the spectra of intact viruses, shows that the observed differences in optical activity can hardly be explained by tryptophan participation in RNA-protein interactions. The presence of the "additional" peak at 293 nm in the ORD of TM virus had been considered as evidence of tryptophan-RNA interactions in this virus. In the present work such a peak at 293 nm was observed in the ORD of all the 5 viruses studied, irrespective of the tryptophan content in their coat proteins. Besides, we managed to obtain the virus-like protein assemblies preparations which also showed a peak at 293 nm. All these data show that, in all probability, the 293 nm peak in the ORD of TM virus does not result from tryptophan-RNA interactions. It is believed that the difference in the optical activity of RNA particles of TM-like viruses do originate from the differences in the RNA-protein interactions in these viruses, but these interactions can hardly involve tryptophan residues of virus coat proteins.


In vivo incorporation of ribosomal proteins into HeLa cell ribosomal particles. Using high salt-washed ribosomal subunits from HeLa cells we detect three ribosomal proteins from the small subunit and five ribosomal proteins from the large subunit that enter ribosomal particles in the absence of ribosome formation (actinomycin D-treated cells); in untreated cells, they enter the ribosomal particles quickly, while the rest of the ribosomal proteins are incorporated gradually. At least two of the large subunit actinomycin D-resistant ribosomal proteins seem to be absent in the 55 S nucleolar ribosomal precursor.


Immunochemical characterization of fibrinogen induction in rat liver. The synthesis of fibrinogen in rat hepatocytes can be induced two to three times  its normal level following an injection of turpentine. Detection of the increased synthesis of this protein was accomplished by quantitative immunoprecipitation analysis. The time sequence for maximal intracellular synthesis occurs more rapidly than the concomitant rise in plasma fibrinogen, implying that the secretion of fibrinogen is somewhat slower than was anticipated. Binding studies with 125I-labeled anti-fibrinogen to the nascent chains on the ribosomes showed no detectable changes in the radioactivity distribution before or after stimulation as analyzed by zone sedimentation. It was estimated that only 4.4% of the total polysomes were involved in fibrinogen synthesis prior to induction and this was increased to 15% following turpentine stimulation. The results suggests that the rise in fibrinogen synthesis during the acute-phase response was related to an increase in functional messenger RNA transcripts rather than in an increase in the rate of protein synthesis.


Intramolecular hydrogen bonding and molecular conformations of nucleosides. N (6)-dimethyl-2',3'-isopropylidene adenosine. The physical properties of an adenosine derivative, N(6)-dimethyl-2',3'-O-isopropylidene adenosine, Derivative 1, which is capable of intramolecular hydrogen bond formation between base-ring and sugar exocyclic hydroxymethyl group, have been studied in solution by infrared, circular dichroic and nuclear magnetic resonance spectroscopy. Analysis of the 220 MHZ 1H NMR spectrum of Derivative 1 in C2HCl2 solution indicated an overwhelming preference for the gg conformation for rotation about the C(4')--C5') bond and a predominant conformation for rotation about the C(5')--O(5') bond in which OH(5') projects towards the base ring. The purine base ring was shown to be in a predominant syn conformation with respect to the sugar ring by 100 MHZ 1H nuclear Overhauser experiments, by analysis of 3J(13C,H1') magnitudes observed in proton-coupled 13C NMR experiments and by CD measurements. Combination of each conformation feature of Derivative 1 in non-polar solvents is consistent with the overall molecular conformation observed in the solid state in which intramolecular hydrogenbonding exists between purine N(3) and the sugar CH2OH group; the presence of a strong intramolecular hydrogen bond was observed by infrared spectroscopy. The sugar ring conformations of 2',3'-O-isopropylidene ribonucleosides were analysed in terms of the pseudorotational properties of the ring; the N and S conformations tend toward to C(2')-exo and C(3')-'exo conformations, respectively, compared to normal ribonucleosides (C(3')-endo and C(2')-endo, respectively). The presence of the hydrogen bond in the derivative is sufficient to promote the S-type conformations (approx. 80%--90%) compared to cases where such a strong hydrogen bond is unlikely to be present approx. 40--50%).


The interaction of adriamycin and its beta anomer with DNA. The results of thermal denaturation, fluorescence, calorimetric and viscosimetric studies on the interaction of adriamycin and its beta anomer with DNA are reported. Whereas all equilibrium, hydrodynamic and thermodynamic measurements are consistent with the proposed intercalative binding model for the adriamycin-DNA complex, the binding mechanism for the reaction of the beta anomer with DNA remains uncertaian. All DNA binding properties of this stereoisomer are substantially different from those of the parent compound. The results suggest that the amino sugar residue of the natural antibiotic may interact stero-specifically with the DNA helix, thus dictating the orientation of the tetracvclic chromophore within the intercalation site. The alteration in the DNA binding capacity and the changes in interactions with DNA following in inversion of configuration at C-1', parallel a lack of biological activity observed for the beta anomer.


Studies of the protein synthetic activity of lysates from HeLa cells incubated in hypertonic medium. When HeLa S-3 cells are incubated with medium made hypertonic by adding NaCl, protein synthesis is inhibited. When the cells are returned to normal conditions protein synthesis is restored. To study the molecular mechanism of this regulation of protein synthesis, lysates were prepared from HeLa S-3 cells grown in minimum essential medium (normal, N); from cells which were incubated with additional (100 mM) NaCl (hypertonic, H); and from cells which were treated similarly in hypertonic medium and then restored to isotonic conditions (hypertonic-isotonic, H-I). Lysates of H cells exhibited reduced endogenous protein synthesis. Studies with mixed lysates from H and N cells implicated that the H lysate did not contain a soluble, non-labile macromolecule (greater than 10 000 daltons) with an inhibitory activity upon the protein synthesis. Analysis by Edman reaction of H lysates showed a reduced incorporation of [35S]methionine into N-terminal suggesting that the initiation step of protein synthesis was affected. However, sucrose gradietn analysis indicated that lysates of H cells were still able to form 80-S initiation complexes with [35S] methionyl-tRNAIMet. The block in initiation was not complete. The lesion could not be reversed by adding post-ribosomal supernatant or a ribosomal salt wash from N cells to ribosomes from the H cells. The data show that the ribosomal fraction is primarily involved in the inhibition.


Cholesterol biosynthesis and 3-hydroxy-3-methyl-glutaryl coenzyme A reductase in cultured glial and neuronal cells. Regulation by lipoprotein and by certain free sterols. Regulation of cholesterol synthesis and, particularly, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase was studied in C-6 glial and neuroblastoma cells. Comparison of rates of incorporation of radioactivity from [14C]-acetate or [3H]mevalonate into digitonin-precipitable sterols indicated that HMG-CoA reductase is the major rate-limiting enzyme in cholesterol biosynthesis in both cell types. HMG-CoA reductase exhibited marked changes in enzymatic activity according to the lipoprotein content of the medium. However, significant differences were observed between the two cell types in the quantitative and temporal aspects of this regulation. Thus, in C-6 glial cells, when total serum lipoprotein was removed from the medium, reductase activity increased by 7-8-fold between 2 and 6 h later. After 24 h reductase activity in cells grown in lipoprotein-poor serum was 20-fold higher than in cells grown in regular serum. In neuroblastoma cells, under similar conditions, reductase activity did not increase at all until cells were in lipoprotein-poor serum for more then 6 h, and after 24 h, enzyme activity in cells grown in lipoprotein-poor serum was only approx. 3-fold higher than that in cells grown in regular serum. Addition of total serum lipoprotein caused a rapid decline in enzymatic activity in both cell types, with a t1/2 of 2-2.5 h; however, the onset of the decline was immediate in the glial cells but delayed 1-1.5 h in the neuronal cells. The critical regulatory component in the total lipoprotein fraction was shown to be contained in the low density lipoproteins for the reductase of both cell types. Regulation of reductase by free sterols was shown in both the glial and neuronal cells. However, effects were more marked and evolved more rapidly in the glial cells. The data thus provide important insight into the regulation of cholesterol synthesis in two cell types which are considered to be good models of neurons and glia of developing brain. The occurrence of more marked and more rapid regulation in the glial than in the neuronal cells is compatible with the important role glia play in brain lipid synthesis. The demonstration of dramatic regulation of HMG-CoA reductase by desmosterol, a sterol found in high concentration in brain early in development, may indicate a heretofore unrecognized role for this sterol in the regulation of cholesterol biosynthesis during maturation. 7-Ketocholesterol was shown to induce in C-6 glial cells a rate of decline of HMG-CoA reductase activity compatible with a t 1/2 of just 20 min. This extremely rapid rate of decline suggests that the effect involves an alteration in catalytic efficiency of the enzyme. The mechanism of this effect remains to be determined.


Fatty acid profiles of phospholipids in rabbit and bovine dental pulp. The fatty acid profiles of purified phospholipids were similar in dental pulp from rabbit and bovine teeth. The characteristic fatty acid profile of each phospholipid was similar to that found in several other mammalian tissues. The ethanolamine phosphoglycerides had high levels of arachidonic acid and docosapolyenoic acids. Phosphatidylserine and phosphatidic acid contained high amounts of stearic acid and low levels of polyunsaturated fatty acids. Phosphatidylcholine and sphingomyelin contained high amounts of palmitic acid and low levels of C20 and C22 unsaturated fatty acids, and sphingomyelin contained C24 fatty acids. Phosphatidylinositol contained mainly stearic, oleic, and arachidonic acids. The fatty acid compositions of the purified pulp phospholipids are markedly different from those reported for dentin lipids which have been reported to contain little or no arachidonic acid and docosapolyenoic acids. The possible significance of the polyunsaturated fatty acids and phospholipids in tooth formation and maintenance is discussed.


Incorporation of saturated fatty acids into phosphatidylcholine bilayers. The transition temperature of dipalmitoylglycerophosphocholine in multi-lamellar aqueous suspensions, as observed by high-sensitivity differential scanning calorimetry, is raised from 41.4 to 61.5 degrees C by addition of palmitic acid at a mole fraction of 0.67. It appears that the fatty acid chains pack in the hexagonal lattice with the lipid chains in a one-to one ratio, thereby eliminating the destabilizing crowding of the phosphatidylcholine head groups. A similar effect on dilauroylglycerophosphocholine is produced by lauric acid. The stabilizing effect is not produced in full measure by acids of different chain lengths, nor by alcohols or saturated hydrocarbons of the same chain length.


Effects of thiamine and pyridoxine on the lipid composition of Saccharomyces carlsbergensis 4228. The lipid composition of Saccharomyces carlsbergensis 4228 cells grown aerobically in the presence of thiamine and absence of pyridoxine was markedly different from that of cells grown without addition of both of the growth factors. In addition to the previous observations showing a reduction in the levels of unsaturated fatty acids (Nishikawa, Y., Nakamura, I., Kamihara, T. and Fukui, S. (1974) Biochem. Biophys. Res. Commun. 59, 777-780) and lack of zymosterol and ergosterol (Nagai, J., Katsuki, H., Nishikawa, Y., Nakamura, I., Kamihara, T. and Fukui, S. (1974) Biochem. Biophys. Res. Commun. 60, 555-560), the thiamine-grown cells were found to contain low levels of total lipids, sterols (especially in the form of esters), triacylglycerols and total phospholipids. However, relative contents of triacylglycerols and phospholipids to total lipids were higher than those of control cells. Hydrocarbons and diacylglycerols accumulated to appreciable degrees. Phospholipid composition was also influenced by thiamine. The ratio of phosphatidylinositol to total phospholipids increased, whereas that of phosphatidylethanolamine decreased. The levels of phosphatidylcholine plus phosphatidylserine decreased in a similar ratio to that of total phospholipids. It was found that unsaturated fatty acid contents were low in all lipid esters tested. The effect of thiamine was particularly noteworthy in the case of sterol esters. Concomitant addition of pyridoxine with thiamine to the medium brought about a normal lipid composition in the yeast cells.


The effect of phosphatidylcholine and lysophosphatidylcholine on the absorption and mucosal metabolism of oleic acid and cholesterol in vitro. The absorption and mucosal metabolism of [14C]oleic acid and [3H]cholesterol were studied using everted sacs of rat jejunum in an in vitro incubation system. The labeled compounds were present in the incubation mixture either singly or together as mixed micelles with bile salt and monoacylglycerol and in the presence or absence of phosphatidylcholine or lysophosphatidylcholine. The presence of cholesterol or phosphatidylcholine markedly suppressed oleic acid absorption. We suggest that both compounds interacted with the micelles causing changes in micellar mass, charge or configuration leading to possible interference with access of the fatty acid to the cell membrane. Lysophosphatidylcholine enhanced oleic acid absorption and stimulated incorporation of the fatty into mucosal triacylglycerol. When the incubation temperature was lowered to suppress metabolism lysophosphatidylcholine had no effect. The results suggest that the increased absorption occurring at the higher temperature was secondary to enhanced glycerol acylation. Lysophosphatidylcholine had only a minimal effect on cholesterol absorption and no effect on cholesterol acylation. Evidence is presented showing that lysophosphatidylcholine is itself well absorbed and variously metabolized. We conclude that phosphatidylcholine and lysophosphatidylcholine have quite divergent effects on lipid absorption but the full elucidation of their mechanisms of action must await further study.


High performance liquid chromatographic separation and direct ultraviolet detection of phospholipids. A fast and efficient method for the separation of (phospho)lipids by high performance liquid chromatography using n-hexane, 2-propanol, water mixtures as the solvent system is described. The lipid separation occurs on a LiChrosorb Si-60 (10 micron) column and the individual components are monitored directly by ultraviolet absorption at 206 nm. Of a total lipid extract from erythrocytes a complete separation is achieved of cholesterol, phosphatidic acid, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, lysophosphatidylcholine and lysophosphatidylethanolamine, whereas phosphatidylcholine and sphingomyelin are only partly separated under these circumstances. Furthermore, a mixture of synthetic phospholipids, i.e. 1,2-dilauroyl-sn-glycero-3-phosphatidic acid, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine, 1,2-dioleoyl-sn-glycero-3-phospho-1'-sn-glycerol and 1,2-dioleoyl-sn-glycero-3-phosphocholine has been completely resolved. In addition to separation of phospholipids in different classes, separation of molecular species can also be achieved in some cases, as is shown for 1,2-dipalmitoleoyl-sn-glycero-3-phosphocholine and 1,2-didocos-13'-cis-enoyl-sn-glycero-3-phosphocholine.


Distribution of prostaglandin biosynthetic pathways in several rat tissues. Formation of 6-ketoprostaglandin F1alpha. The capacity of homogenates of rat lung, liver, spleen, whole stomach, stomach fundus, kidney and heart to form prostaglandin E2, F2alpha, D2, thromboxane B2 and 6-ketoprostaglandin F1alpha was investigated. All products were quantitated by mass spectrometry. The results demonstrated interesting differences between tissues in the direction of the 'prostaglandin synthetase' to specific products (e.g. as in spleen and stomach).


Cancer mortality correlation studies--III: statistical associations with dietary selenium intakes. Age-corrected mortalities from cancer at 17 major body sites were correlated with the apparent dietary selenium intakes estimated from food-consumption data in 27 countries. Significant inverse correlations were observed for cancers of large intestine, rectum, prostate, breast, ovary, lung and with leukemia; weak inverse associations were found for cancers of pancreas, skin and bladder. Similar inverse corelations were found between cancer mortalities at the above sites and the selenium concentrations in whole blood collected from healthy human donors in the U.S. and different countries. The results support the hypothesis that selenium has cancer-protecting effects in man. Other studies are cited which demonstrate that selenium prevents or retards tumor development in animals. A change of diet aimed at increasing the dietary selenium supply is suggested as a possible means of lowering the human cancer risk. It is postulated that the cancer mortalities in the U.S. and other Western industrialized nations would decline significantly if the dietary selenium intakes were increased to approximately twice the current average amount supplied by the U.S. diet.


Cancer mortality correlation studies--IV: associations with dietary intakes and blood levels of certain trace elements, notably Se-antagonists. The per-capita intakes of zinc, cadmium, copper and of chromium were estimated from food consumption data in 28 countries and were found to correlate directly with the age-corrected mortalities from cancers of intestine, prostate, breast, leukemia, skin and of other organs, suggesting that the anticarcinogenic effect of selenium is counteracted by other trace elements. Similarly calculated dietary intakes of manganese are inversely correlated, particularly with the mortalities from cancer of pancreas, an organ normally known to contain high concentrations of this element. Arsenic intakes correlate inversely with the male lung cancer mortalities. A number of other direct and inverse associations were observed which suggest that trace elements in the human diet may hav both benign and adverse effects on tumor development. The zinc concentrations in whole blood collected from healthy donors in the U.S. correlate directly with regional mortalities from cancers of intestine, breast and of other sites. The origin of these associations is discussed primarily in terms of the seleium-antagonistic effect of zinc and of some of the other elements considered. Results of animal experiments and of other studies are cited which support hypotheses that link human cancer development to possible deficiencies or excesses in the dietary trace element intakes.


Concerning the metalloenzyme ascorbate oxidase. Apoascorbate oxidase has been shown to have a molecular weight of 137,000 +/- 3,000 and essentially the same gross quaternary conformation as native ascorbate oxidase. The apoenzyme, however, lacks much of the conformational stability of the native enzyme. The removal of the copper from the oxidase protein, and the simultaneous reduction of the disulfide bonds results in an apoenzyme of lower structural stability than the native oxidase. The aging of apoascorbate oxidase has been found to involve a loss of ionizable tyrosine residues and a dissociation to subunits and component polypeptide chains, which was not observed with the more stable native and holo enzymes. The molecular weight of holoascorbate oxidase has been determined to be 285,000. An s020, w of 9.79 has been determined for the holoenzyme. Holoascorbate oxidase has been shown to have an electrophoretic mobility on polyacrylamide gels that is 23% lower than either the native or apoenzyme. Furthermore, electrophoresis of the holoenzyme, in buffers containing dodecyl sulfate, and also isoelectric focusing of the holenzyme, produce patterns of greater similarity to those of apoascorbate oxidase than the native enzyme.


Radiation-induced inhibition of eclosion in the tobacco hornworm, Manduca sexta. Control of eclosion in Manduca sexta (laboratory reared at 23-25 degrees C on 18L:6D) was investigated by utilizing the ED50 (X-ray exposure required to prevent eclosion in 50% of the irradiated animals) throughout pupal-adult development as a measure of radiation sensitivity. An initial period (day 0-6) of nearly constant radiosensitivity (ED50 range: 13.0-14.4 kr) was followed by a brief period of increased radiosensitivity between day 6.5-7.75 (ED50:8.23 kr). Thereafter, a pronounced decrease in radiosensitivity was noted through the day of eclosion (day 8: ED50 = 19 kr; day 22: ED50 = 75 kr). The association between hemolymph ecdysone levels and maximum radiosensitivity observed on day 7 was studied. Animals administered beta-ecdysone on days 1, 4, and 12, and irradiated at various times post-injection, exhibited significant increases in radiosensitivity exhibited by Manduca sexta on days 0-7 is in part dependent upon the titer of ecdysone in hemolymph. The role of the brain as a radiosensitive region was investigated in day 10 animals by selectively transplanting ED100-irradiated and nonirradiated brains into ED100-irradiated and nonirradiated animals. The presence of a radiosensitive component in addition to the brain is proposed since the radiation-induced inhibition of eclosion could not be completely explained in terms of brain damage alone. Selective shielding of day 10 animals X-irradiated at an ED100 level demonstrated the absence of radiosensitive regions in the abdomen and their presence in both the head and thorax.


Temperature relations of aerial and aquatic respiration in six littoral snails in respiration in six littoral snails in relation to their vertical zonation. Aerial and aquatic rates of oxygen consumption were determined over a range of 5 degrees to 45 degrees C at 5 degrees C intervals for six species of marine littoral snails: including the sublittoral species, Acmaea testudinalis, Mitrella lunata, and Lacuna vincta; and the truly intertidal species, Littorina obtusata, L. littorea, and L. saxatilis. Polarographic oxygen electrodes were used with normally active snails collected from populations on Nobska and Manomet Points, Massachusetts. Three subtidal species, A. testudinalis, Lacuna vincta, and M. lunata, do not display any metabolic adjustment to increasing temperature, with thermal limits reached at 30 degrees to 35 degrees C. Aerial respiration in A. testudinalis is similar to aquatic O2 uptake, but rates average only 36.4% of aquatic rates. The intertidal congeners, Littorina obtusata, L. littorea and L. saxatilis, have varying degrees of aerial and aquatic metabolic regulation with increasing temperature. L. obtusata, a low intertidal snail exposed to air for 15% to 45% of the tidal cycle, displays a respiratory pattern of "passive endurance" to high temperatures both in air and in water. L. littorea, the dominant snail of the midlittoral region, remains active when exposed to air (30% to 75% of the tidal cycle) and has a zone of metabolic regulation between 20 degrees C and 30 degrees C. Over this, the normal ambient temperature range, the Q10 closely approximates one, and nearly equivalent O2 uptake rates occur in air and in water. L. saxatilis from the upper littoral region is exposed to air for 70% to 95% of the tidal cycle and is characterized by reduced aerial and aquatic O2 uptake rates above 25 degrees C, representing a reversible torpor up to its thermal maximum at 44 degrees C. For these six snail species, respiratory responses to increasing temperature are thus directly related to the pattern of vertical distribution in the intertidal environment. Discussion of this relationship stresses that the evolution of other nearterrestrial structures and functions in littoral snails has proceeded in a discontinuous fashion. Despite this, the temperature responses in respiration parallel the functional morphology of the pallial structures and the physiological patterns of response to low oxygen stress, as well as adaptive features of reproduction, larval development, water-control, and nitrogenous excretion.


Hormonal control of reproduction in Busycon: laying of egg capsules caused by nervous system extracts. Mature specimens of female Busycon laid egg capsules when injected with extracts of nervous systems of male or female Busycon. The substance causing this behavior, named egg capsule laying substance (ECLS), was found most reliably in parietal ganglia, less consistently in cerebral-pleural ganglia, and rarely in other ganglia. Both species of Busycon found in Woods Hole, B. canaliculatum and B. carica, contained ECLS, and ECLS of each species was active in the other. ECLS activity was not destroyed by boiling for up to fifteen minutes. Centrifugation of nervous system extracts at 105,000 X g yielded ECLS only in the pellet. ECLS was not released from the pellet by freeze-thawing or by 1.0 M NaCl, but could be partially solubilized by boiling extracts before centrifugation. ECLS activity was destroyed by protease. Several animals "spontaneously" laid strings of egg capsules after being put in a group tank with males and other females. Approximately the first ten capsules laid by these animals were devoid of eggs, after which egg-containing capsules were laid. Injection of ECLS into a spontaneous egg layer within a few hours after cessation of spontaneous egg laying caused the laying of capsules containing eggs. The possibility that ECLS may normally be responsible for the laying of both eggs and egg capsules is discussed.


Limb regeneration in fiddler crabs: species differences and effects of methylmercury. 1. When kept under identical conditions, Uca pugnax regenerates limbs and molts more rapidly than U. pugilator from the same location. 2. The tropical species U. rapax and U. speciosa also regenerate faster than U. pugilator from the same location. U. thayeri is the slowest to replace missing limbs, the slowest to harden the carapace after ecdysis, and also requires the greatest injury before autotomy will take place. 3. When kept in groups, U. thayeri stops regeneration after basal growth and will not molt; U. pugilator is only slightly retarded when kept in groups. U. rapax is also affected by grouping, showing a lengthened proecdysial phase and terminal plateau, thus also delaying molting. 4. Newly regenerated limbs of U. rapax, U. thayeri, and U. speciosa, aside from being lighter than old limbs, have a conspicuous banding pattern. This pattern becomes less obvious during the week or two after ecdysis as melanophores move into the interband regions and the limb as a whole darkens due to increased dispersion of pigment in the melanophores. In U. pugilator the newly regenerated limbs are very pale in color and remain that way for several months under laboratory conditions, even when animals are maintained on a dark background. 5. When treated with 0.5 mg/liter methylmercury, growth was inhibited entirely in U. thayeri. Partial inhibition was seen in U. pugilator, and the least inhibition in U. rapax. A few individuals of U. rapax were able to complete regeneration and molt, but there was no melanin in the regenerated limbs. 6. Inhibition of melanogenesis in regenerated limbs was also seen in U. thayeri and to a smaller extent in U. pugilator at 0.1 mg/liter methylmercury. The lack of black pigment may be due to an inhibition of cell migration but more likely of melanin synthesis. Some of these crabs developed melanin when kept in clean water after ecdysis. 7. Seasonal differences were noted in all species, but especially in U. Thayeri. In this species, regenerated occurred much more rapidly in March-April than in January.


Characteristics of influex and net flux of amino acids in Mytilus californianus. 1. Intact mussels and an in vitro preparation of isolated gill tissue were employed to study characteristics of the influx and net flux of amino acids in Mytilus californianus. 2. The kinetics of influx of 14C-labelled amino acids were complicated by the presence of a rapidly labelled extracellular compartment. 3. Correction of influx data for the extracellular compartment revealed influx of 14C-cycloleucine and 14C-glycine to be mediated by a transport mechanism adequately described by Michaelis-Menten kinetics. Passive diffusion plays no significant role in influx. 4. Influx and net flux of glycine into intact Mytilus were examined. From high concentrations (greater than 20 micronM) the influx of 14C-glycine was equivalent to the net influx of primary amine as determined by fluorescamine. At low ambient concentrations (greater than 20 micronM), influx of 14C-glycine occurred more rapidly than net influx as determined by fluorescamine. The data suggest that influx of labelled substrate is accompanied by efflux of unknown primary amine(s). In the absence of labelled substrate, efflux continues until a steady-state concentration of 2-5 micronM in the medium is achieved.5. The rate of influx of 14C-cycloleucine into isolated gill tissue, and the concentration gradient which can be developed by gill tissue are reduced when sodium is replaced in the medium. 6. The efflux of primary amines from isolated gill tissue is stimulated by the replacement of sodium in the medium with choline. 7. The data are consistent with a sodium-coupled mechanism for the transport of amino acid into gill tissue. However, energetic considerations cast doubt on the adequacy of such a mechanism to account fully for the observed trans-epidermal transport.


[Isolation, analysis and characterization of microsomal ghost fractions]. A new method of isolating the microsomal ghost fractions has been developed. The membranes were purified from adsorbed protein, ribosomes and intravesicular content. The purified membranes contained 6 times less RNA than did the original microsomes. The phospholipid:protein ratio in the ghosts increased from 0.34 to 0.80. Protein electrophoretic pattern ghost was more homogenous than that of microsomes. SDS-polyacrylamide electrophoresis showed that the ghosts contain 11 fractions as compared to 21 in microsomes. A high degree of membrane purification did not affect the inactivation of microsomal enzymic systems. Practically all cytochrome P-450 in the ghosts was found in its active form. The activities of NAD(P)H-dependent systems of dimethylaniline and ethylmorphine demethylation, p-hydroxylation of aniline were well retained. The removal of non-membrane protein allows to obtain an electrone microscope picture of the lipid bilayer as a structural basis of microsomal membrane.


[Study of the kinetic mechanism of the pyruvate-2,6-dichlorophenolindophenol reductase activity of muscle pyruvate dehydrogenase]. The mechanism of pyruvate-2,6-dichlorophenol-indophenol (2,6-CPI) reductase reaction catalyzed by the pyruvate dehydrogenase complex from pigeon breast muscle and by its pyruvate dehydrogenase component was studied. The K'm values for 2,6-DCPI in both cases were found equal to 1.3--1.4-10(-5) M. The double reverse values plots obtained at a fixed concentration of the first substrate and a variable concentration of the second one were linear and had a constant K'm/V'max ratio. The substitution of thiamine pyrophosphate and pyruvate by the substrate decarboxylation product, i.e. 2-oxyethyl thiamine pyrophosphate under similar conditions resulted in kinetic plots, typical for the "ping-pong" mechanism of enzymatic reactions. A mechanism of the pyruvate 2,6-DCPI reductase reaction, providing for the interaction of 2-oxyethyl thiamine pyrophosphate after its binding to the apoenzyme with a certain protein group of the pyruvate dehydrogenase active centre, was postulated. The reaction was shown to result in the production of acetyl-substituted reduced form of the enzyme. Regeneration of free enzyme required the presence of 2,6-DCPI as oxidizing agent.


[Sensitivity of B- and C-DNA forms to modifications by O-methylhydroxylamine]. Effects of high concentrations of lithium, cesium and ammonium chlorides on the reaction ability of free CMP and cytosine in free DNA of CD phage with respect to O-methylhydroxylamine (OMHA) are studied. CMP reaction in all the cases takes place mainly for 24 hours. Like classical B-form, native DNA, having C-form in high ionic strength solution (as estimated from circular dichroism data), is not modificated. Thus, the access of some cytosine residues in intraphage DNA to OMHA is due not to the decreased DNA hydratation in situ, but to the presence of differently ordered regions in DNA.


[Substrate specificity of sweet almond beta-glucosidase]. Beta-Glucosidase, beta-galactosidase, beta-xylosidase and alpha-L-arabinosidase activities of partially purified preparation of almond emulsin were investigated using chromatography, electrophoresis in polyacrylamide gel and isoelectric focusing. Beta-Glucosidase was found to exist as two components having equal molecular weight. Aggregation of the components with inactive proteins probably results in the appearance of multiple native forms which have similar specific activities. In no case separation of the beta-glucosidase activity from the accompanied activities was achieved. It is concluded therefore that these activities are exhibited by an enzyme which is not strictly specific to the C4, C6 stereochemistry for hexosides and to that of C4, C5 for pentozides.


[Subcellular distribution of arginase and gamma-guanidino-butyrate-ureohydrolase in brain sections, neurons and glia]. Distribution of arginase and gamma-guanidine-butyrate-ureohydrolase in seven brain sections is studied. Specific activity of arginase in brain sections is 0.063-0.117 and of gamma-guanidine-butyrate-ureohydrolase -- 0.042-0.050 mcmoles of urea per 1 mg of protein for 30 min. Cortex and cerebellum neurons have the same arginase activity (0.12 mcmole/mg). Specific arginase activity in glial cerebellum cells is 3 times as much as in cortex glial cells (0.20 and 0.07 mcmole/mg respectively). The activity of gamma-guanidine-butyrate-ureohydrolase in glial cell is higher than in neurons. Subcellular distribution of both enzymes is studied in those brain sections where their activity is maximal. In cerebellum both enzymes were tested, in cortex -- gamma-guanidine-butyrate-ureohydrolase, in thalamus -- arginase. The highest specific arginase activity is found in cytoplasmic, microsomic and synaptosomic fractions. Gamma-Guanidine-butyrate-ureohydrolase is concentrated in cytoplasmic and synaptosomic fractions. Possible correlation of gamma-aminobutyric acid metabolism and participation of brain arginase in regulation of protein biosynthesis are discussed.


[Studies on protein biosynthesis in the silk gland of Bombyx mori L. silkworm]. The incorporation of (14C) lysine (to characterize the biosynthesis of cellular proteins) and (14C) glycine (for silk fibroin) in free and membrane-bound polyribosomes was studied in fibroin portion of the silk gland of Bombyx mori silkworm in the V instar. It was shown that although the membrane-bound polyribosomes are found in posterior silk gland from the beginning of the V instar, the fibroin biosynthesis in the membranebound polyribosomes takes place predominantly in the second part of the V instar. On the other hand the cellular proteins are synthesized mostly in the free polyribosomes in the first half of the V instar. In the second half of the V instar in the sucrose gradient zone corresponding to free polyribosomes, monoribosomes unable to synthesize protein for the absence of mRNA are present. Nevertheless, these ribosomes isolated from the fibroin part of the silk gland in the end of the V instar do synthesize polyphenylalanine in the presence of poly (U), and aminoacyl-t-RNA-synthetases and tRNA's obtained from the posterior silk gland.


[Modification of phosphorylase b histidine residues by diethylpyrocarbonate]. Interaction of phosphorylase B with diethylpyrocarbonate was studied. It was found that modification of the histidine residues is accompanied by a change in the adsorption spectrum of phosphorylase B at around 240--245 nm, as well as by inhibition of the enzyme activity. The addition of hydroxylamine to the modified protein results in an elimination of the absorption at round 240 nm and a complete restoration of the enzyme activity. The apparent constants of the phosphorylase B inactivation rates and the rates of the histidine residues modification are shown to be the values of the same order. In the presence of substrate (glucose-1-phosphate) one of the histidine residues (calculated per 1 subunit) does not enter the reaction with diethylpyrocarbonate, a protection of the enzyme against inactivation being observed. In the presence of activator (AMP) four histidine residues are inaccessible for diethylpyrocarbonate; however, the degree of inhibition of the enzyme activity does not change. The phosphorylase B molecule, modified in the presence of AMP, is incapable of dissociating into monomers.


[Isolation and properties of glycogen phosphorylase b from rabbit liver]. Purification of dephosphorylated form of rabbit liver glycogen phosphorylase (phosphorylase b) has been carried out. The purification procedure included 3 steps:sedimentation of protein-glycogen pellet by centrifugation at 62 000 x g during 2 hours, chromathography on omega-amino-hexyl-Sepharose column and isoelectric focusing. The yield of the enzyme is about 60%, the specific activity at glucose-1-phosphate concentration 100mM is 35 mkmol of Pi/mg protein-min. The final preparation revealed apparent homogeneity during ultracentrifugation and polyacrylamide gel electrophoresis. The subunit molecular weight of 100 000 was determined by disc-electrophoresis in the presence of sodium dodecyl sulfate. The absorption spectrum of liver phosphorylase b shows a protein maximum at 280 nm and a second peak at 333 nm produced by bound PLP. A kinetic analysis of initial rates with variable concentrations of the substrate revealed the homotropic cooperativity of glucose-1-phosphate binding sites. This cooperative effect is more pronounced in the presence of inhibitors, glucose and ATP and less pronounced in the presence of AMP.


[Effect of kininogen on the activity of human blood serum kininogenase system]. The inhibitory effect of kininogen (especially its high molecular form) on kallikrein esterase activity and on the process of kallikreinogen auto-activation is demonstrated. Kallikreinogen and kininogen from human blood serum partially purified on QAE-Sephadex. CM-Sephadex and G-200 Sephadex were used in experiments.


[Activation of plasma Factor XIII by acetylated thrombin]. It has been demonstrated that acetylated thrombin (thrombin-esterase), having practically no coagulating activity but possessing high esterase activity, is capable to activate factor XIII. This ability, however, is 2 times lower as compared to that of native thrombin.


[Peculiarities of primary and secondary structure of phage FI-1 DNA]. The composition of nitrous bases of phage FI-1 DNA was studied. As is evidenced from the values of buoyant density in CsCl (p=1,7093 g/cm(3)), melting temperature (T degrees m=86,05 degrees), spectral parameters and direct chromatographic determination, the DNA analysed contains 41,5 mole% pairs of guanine-cystosine. 5-hydroxymethylcytosine and other anomalous bases were not found. Chemical identification and jaxtposition of data of buoyant density in CsCl and Cs2SO4 (p=1,4466 g/cm(3)) and T degrees m. showed the presence of the extra-sugar component in DNA, most likely in the form of hentibiose. Spectral character of thermal denaturation of DNA in different solvents is indicative of the double helixity of its structure. DNA is characterized by enthalpies of conformational transitions "helix coil" (deltaH=12,3 kcal/g) and (deltaH=10 kcal/g) for the solvents, 1 x SSC, and 0,1 x SSC, correspondingly. The presence of extra-sugar in DNA with standard set of nitrous bases is discussed.


Hydrolytic enzymes in colorectal cancer. Activities of sulphatases A/B, sulphatase C, beta glucuronidase, acid and alkaline phosphatase were measured in 38 cases of colorectal cancer. A wide variation in the levels of individual enzymes was observed, suggesting that certain patients might benefit from therapy with tailor made enzyme activated anti-tumour agent. The activity of sulphatase C was correlated with the other lour, but the enzyme profile could not predict the evofution of the disease.


Lynestrenol, an amplifier of lymphocyte stimulation. Lynestrenol, a synthetic steroid progesterone-like substance, has been found to enhance the stimulation of normal human lymphocytes. It increases the phytohemagglutinin response and the mixed-lymphocyte cultures. This augmentation can, in some cases, be higher than 100% of the phytohemagglutinin or mixed lymphocyte reaction baseline. There is no significant effect on the pokeweed mitogen stimulation. It is concluded that lynestrenol can modulate, "in vitro", some T cell functions.


Inhibition of prolactin release by metergoline administration in man. Oral administration of metergoline, an antiserotoninergic agent, produced a fall in plasma prolactin concentrations in normal subjects. Prolactin values remained suppressed during a five day course of treatment with the drug. Serum growth hormone values were not altered significantly.


Comparative study of urinary excretion rates of para-hydroxy-mandelic acid, homovanillic acid, vanylmandelic acid in cirrhotic patients with and without encephalopathy. A comparative study of urinary excretion of octopamine, dopamine, and noradrenaline catabolic products, respectively parahydroxymandelic acid (PHMA) homovanillic acid (HVA) and vanylmandelic acid (VMA) was carried out in 27 cirrhotic patients with (11) and without (16) porto-systemic encephalopathy (P.S.E). PHMA, HVA and VMA were significantly higher in patients with PSE, and there was a positive correlation between PHMA and HVA, and between PHMA and VMA. Higher excretion of PHMA in patients with PSE strongly suggests an increased metabolism of octopamine. HVA and VMA increased excretion, and the positive correlations could be explained by the depletion of stored dopamine and noradrenaline. These observations support the hypothesis that octopamine acts as a false neurotransmitter, and the resulting depletion of dopamine and noradrenaline could explain the neuropsychic phenomena of PSE, and the awakening effect of L. Dopa treatment.


Cutaneous response to dinitrochlorobenzene in patients with genito-urinary cancers. The aim of the present study is to analyse the response in patients with cancer of the urogenital region to a primary antigen 2-4 dinitrochlorobenzene (DNCB). A total of 69 patients with neoplastic disease were studied (13 cases with kidney cancer, 34 cases with bladder cancer, 13 cases with prostatic cancer, 5 cases with testicular cancer, one case with penis cancer, and 3 cases with cancer of the cervix, comparatively with 13 patients with non-malignant urological diseases. Whereas in the control group, 78% of the patients gave a positive skin reaction to DNCB, 15% of the patients with kidney cancer, 56% of the patients with bladder cancer, 69% of the patients with prostatic cancer and 60% of the patients with testicular cancer gave a positive reaction.  If we consider the stages of the disease, the reaction was positive, in 91% of bladder cancer at stage I and in 47% at stages II and III in 100% of prostatic cancer at stage I and in 62% at stages II and III, in 60% of testicular cancer at stage IV (but 100% of seminomas and 0% of dysembryomas have a positive reaction). It would therefore seem that a correlation exists between the degree of the extension of the disease and the skin reaction to DNCB.


Decrease in magnetic anisotropy of external segments of the retinal rods after a total photolysis. The magnetic anisotropy of a polymembrane cell, such as the external segment of the frog retinal rod, is defined as the difference between the axial magnetic susceptibility (chiar), chia - chir = deltachi of the segment. After the total photolysis of the rhodopsin in situ, deltachi decreases a significantly by 20%. This decrease in magnetic anisotrophy should involve a subtle molecular disorder, mostly due to an alteration of the rhodopsin molecule.


The facilitated diffusion of oxygen by hemoglobin and myoglobin. We have clarified the use of Wyman's differential equation for the facilitated oxygen flux through a slab of solution of myoglobin or hemoglobin by showing that there is a unique choice of boundary condition on the carrier concentration to be employed in conjunction with it. The singular perturbation solution of Wyman's equation, due to Murrayand Mitchell and Murray, has been extended. By means of it, the paradox of Wittenberg, that the facilitated oxygen flux per mole of heme is apparently independent of the protein carrier, has been resolved.


Unstirred layer effects on calculations of the potential difference across an ion exchange membrane. The potential difference between two solutions of the same 1:1 electrolyte bathing an ion exchange membrane has been calculated as the sum of the following components: (a) a Donnan potential at each membrane-solution interface, (b) a diffusion potential within the membrane phase, and (c) a diffusion potential in the unstirred layer on each side of the membrane. For a highly charged ion exchange membrane with at least one surface in contact with a dilute solution, calculated transmembrane potential differences are extremely sensitive to the assumed thickness of the unstirred layers. This sensitivity to unstirred layer thickness is primarily due to changes in the Donnan components of the potential difference. By this approach, it was possible to fit membrane potential data from Gunn and Curran (1971, Biophys. J. 11:559) for a range of bathing solution concentrations from 0.0016 to 4.0 M. If no effort was made to account for the modification of the Donnan potentials by the presence of unstirred layers, the data appeared incompatible with an electrodiffusion equation description. Suggestions for a more stringent experimental test and a brief discussion of possible implications for electrical measurements on fresh-water giant algal cells are presented.


Neural repetitive firing: modifications of the Hodgkin-Huxley axon suggested by experimental results from crustacean axons. The Hodgkin-Huxley equations for space-clamped squid axon (18 degrees C) have been modified to approximate voltage clamp data from repetitive-firing crustacean walking leg axons and activity in response to constant current stimulation has been computed. The m infinity and h infinity parameters of the sodium conductance system were shifted along the voltage axis in opposite directions so that their relative overlap was increased approximately 7 mV. Time constants tau m and tau h, were moved in a similar manner. Voltage-dependent parameters of delayed potassium conductance, n infinity and tau n, were shifted 4.3 mV in the positive direction and tau n was uniformly increased by a factor of 2. Leakage conductance and capacitance were unchanged. Repetitive activity of this modified circuit was qualitatively similar to that of the standard model. A fifth branch was added to the circuit representing a transient potassium conductance system present in the repetitive walking leg axons and in other repetitive neurons. This model, with various parameter choices, fired repetitively down to approximately 2 spikes/s and up to 350/s. The frequency vs. stimulus current plot could be fit well by a straight line over a decade of the low frequency range and the general appearance of the spike trains was similar to that of other repetitive neurons. Stimulus intensities were of the same order as those which produce repetitive activity in the standard Hodgkin-Huxley axon. The repetitive firing rate and first spike latency (utilization time) were found to be most strongly influenced by the inactivation time constant of the transient potassium conductance (tau b), the delayed potassium conductance (tau n), and the value of leakage conductance (gL). The model presents a mechanism by which stable low frequency discharge can be generated by millisecond-order membrane conductance changes.


Three steady state situation in an open chemical reaction system I. In an isothermal continuously stirred tank reactor (open chemical reaction system) fed by sulphuric acid solutions of bromate, bromide and cerium (III) bistability (three steady state situation) is experimentally observed. This remarkable behavior, based on the instability of one steady state, has important consequences for the understanding of excitability and biochemical control mechanisms. The mass-balance equations for the reactor and the chemical mechanism of the reaction are combined into a simple mathematical model. The behavior of the resulting nonlinear differential equations is examined analytically and by a graphical integration procedure (method of isoclines). Using realistic kinetic data, the model shows the same behavior as observed in the experiment.


Structural changes and fluctuations of proteins. I. A statistical thermodynamic model. A general theory of the structural changes and fluctuations of proteins has been proposed based on statistical thermodynamic considerations at the chain level. The "structure" of protein was assumed to be characterized by the state of secondary bonds between unique pairs of specific sites on peptide chains. Every secondary bond changes between the bonded and unbonded states by thermal agitation and the "structure" is continuously fluctuating. The free energy of the "structural state" that is defined by the fraction of secondary bonds in the bonded state has been expressed by the bond energy, the cooperative interaction between bonds, the mixing entropy of bonds, and the entropy of polypeptide chains. The most probable "structural state" can be simply determined by graphical analysis and the effect of temperature or solvent composition on it is discussed. The temperature dependence of the free energy, the probability distribution of structural states and the specific heat have been calculted for two examples of structural change. The theory predicts two different types of structural changes from the ordered to disorderd state, a "structured transition" and a "gradual structural change" with rising temperature. In the "structural transition", the probability distribution has two maxima in the temperature range of transition. In the "gradual structural change", the probabilty distribution has only one maximum during the change. A considerable fraction of secondary bonds is in the unbounded state and is always fluctuating even in the ordered state at room temperature. Such structural flucutations in a single protein molecule have been discussed quantitatively. The theory is extended to include small molecules which bind to the protein molecule and affect the structural state. The changes of structural state caused by specific and non-specific binding and allosteric effects are explained in a unified manner.


Self-association of oxyhaemoglobin. A nuclear magnetic relaxation study in H2O/D2O solutions. The proton and deuterium longitudinal relaxation rates were studied at room temperature up to the highest protein concentrations in oxyhaemoglobin solutions of different H2O/D2O composition. The deuterium relaxation rates followed the experimentally well known single linear dependence on protein concentration, the slopes being little influenced by solvent (D2O/H2O) composition. The proton relaxation rates show two different linear dependences on haemoglobin concentration. The entire concentration range is described by two straight lines with the threshold concentration about 11 mM (in haem). The ratio of the slopes is 1.6 (high-to-low HB-conc). Only in the higher concentration range two T1's were observed if the solvent contained more than half of D2O. The slow relaxation phase of protons has T1's similar to those measured in solutions with less than half of D2O. The relaxation of the other phase was ten times faster. The ratio of the proton populations in these two phases was equal to 2 (slow-to-fast) and independent of protein concentration. The fast relaxing protons are attributed to water molecules encaged within two or more haemoglobin molecules which associate for times long enough on the PMR time-scale.


Degradation of polysaccharides by endo- and exoenzymes: dextran-dextranase model systems. Experiments were carried out on dextran-dextranase systems to test the prediction of a mechanistic model recently proposed by us, for the synergistic effect of combined exo/endo enzymic action in the degradation of polymeric substrates. Soluble forms of the substrate were used. Preliminary experiments with an insoluble form of the substrate were also carried out to demonstrate the applicability of the analytical techniques to these cases. Molecular weight distributions of the degradation products were determined (by gel-permeation chromatography) and the rates of production of glucose and of other reducing sugars were also measured. It was found that the exodextranase alone had very little effect on the molecular weight distributions compared to a significant shift towards lower molecular weights obtained with the endodextranase which was synergistically enhanced by the action of the combined enzymes. Glucose was produced more rapidly by the exoenzyme compared to the endoenzyme, but combinations of the two enzymes gave a rate enhancement greater than the linear sum of the effects of the two individual enzymes. In comparing the degradation indices and polydispersities of the various degradation products, similar synergistic effects of the combined enzymes in accordance with the theoretical predictions, were observed. The practical implications of these findings to the design of fermentation processes which depend on the action of endo- and exoenzyme mixtures are noted.


Kinetics of phosphate limited algal growth. The kinetics of phosphate limited growth of two green algae Chlorella pyrenoidosa and Selenastrum capricornutum have been studied in chemostats. Several kinetic models which express the specific growth rate as a function of the intracellular phosphorus content have been examined, and one of the models was found to be significantly better than the other models. The principles of this model were described in a recent paper by Nyholm. The kinetics of phosphate uptake have been investigated by adding pulses of phosphate to the chemostats, The uptake by phosphorus deficient cells could be described by Michaelis-Menten kinetics for phosphate concentrations below approximately 500 microng P/liter. Further, with the assumption of a discontinuous adjustment of the uptake rate at the onset of phosphorus deficiency, a complete kinetic model for growth and phosphate removal is proposed. The mean cell size and the contents of chlorophyll a and RNA per unit dry weight have been measured for C. pyrenoidosa as a function of the dilution rate.


Oxygen transfer and axial dispersion in an aeration tower containing static mixers. Oxygen transfer from gas to liquid under steady-state cocurrent flow conditions was modeled using the dispersion model, and the oxygen transfer coefficients were estimated from available data for a column with Koch motionless mixers. The dispersion in the column was estimated for several different gas and liquid flow rates using steady-state tracer experiments. The estimated oxygen transfer coefficients were compared with those estimated using complete mixing and plug flow models. The results indicate that the dispersion model is the most appropriate model for estimating the mass transfer coefficient from the available data.


SCP production by Chaetomium cellulolyticum, a new thermotolerant cellulolytic fungus. Chaetomium cellulolyticum, a newly isolated cellulolytic fungus, showed 50-100% faster growth rates and over 80% more final biomass-protein formation than Trichoderma viride, a well-known high cellulase-producing cellulolytic organism, when cultivated on Solka-floc (a purified, predominantly amorphorous form of cellulose) or partially delignified sawdust (consisting of a mixture of hardwoods) as the sole-carbon source in the fermentation media. However, in both cases, T, viride produced much higher quantities of free cellulases at faster rates and also degraded more substrate than C. cellulolyticum. It is concluded that the synthesis mechanisms and/or the nature of the cellulase complexes of the two types of organisms are quite different such taht C. cellulolyticum is more optimal for single-cell protein (SCP) production, while T. viride is more optimal for the production of extracellular cellulase. It was also found that the amino acid composition of C. cellulolyticum is generally better than that of T. viride and compares favorably with those of the FAO reference protein, alfalfa, and soya meal. In addition, preliminary feeding trials on rats have shown no adverse effects of the SCP produced by C. cellulolyticum fermentations.


Evalulation of thalidomide children.

Evalulation of thalidomide children. All children suffering from thalidomide embryopathy should undergo a careful clinical and radiographic follow-up examination. This frequently detects hidden defects, especially of the spine and hip joints. It is clear that defects are frequently present, though unsuspected by the clinical examination. A special problem which needs further investigation is the alteration of the knee joints, which has also often been overlooked; Early osteoarthritis is expected to occur in the future. There is an urgent need for additional study of the general functional capacity and also the manual efficiency of the children under consideration for their occupational integration. We shall be engaged with this problem in future studies.


[Reactions of intra- and extracrenial vessels to noradrenaline in experimental cardiogenic shock]. Decrease in the constrictive reaction of the intra- and extracranial vessels to noradrenaline was observed in animals with cardiogenic shock; in acute experiments on anesthetized cats by resistography and rehoencephalography. Under these conditions the rise of the systemic arterial pressure under the influence of noradrenaline promoted passive dilatation of the cerebral vessels and an increase of their blood filling.


[Age and biosynthesis and breakdown of thrombocyte proteins]. Platelet protein biosynthesis and catabolism in adult and one-month-old rabbits was studied with lysine-14C in vivo. Free radiolysine-14C failed to pass through the membrane of the circulating blood platelets, and its appearance within the platelets was possible only at the stage of platelet production. Platelet protein synthesis in one-month-old rabbits was shown to be slower than that of adults. The half-life period of platelet protein in adults averaged 2 days and in one-month-old rabbits-3 days. Slowing down the platelet protein circulation was noted at the early postnatal ontogenesis.


[Dynamics of changes in hexokinase activity in subcellular tissue fractions of hypoxic newborn rats]. The activity of hexokinase (HK) in the total homogenate, cytoplasmic and mitochondrial fractions of the brain, heart and liver of the newborn rats was studied in relation to the severity of the hypoxic action. A mild from of hypoxic hypoxia caused in the tissue of the brain and liver an increase in the activity of mitochondrial-bound form of the enzyme with a simultaneous fall in the activity of the cytoplasmic HK; this was accompanied by a marked acceleration of glucose phosphorylation in the brain. Severe hypoxia led to the reduction of the HK activity in the total homogenate and both intracellular fractions in all the tissues under study. The data obtained pointed to disturbance of some adaptive mechanisms in severe hypoxia in the tissues of the newborn rats.


[Effect of a new cholinesterase reactivator, diethixime, on the central nervous system]. A new cholinesteras reactivator--chlorohydrate of S-diethylaminoethyl ether p-bromo benzoylthiohydroxime acid (diethixime), containing a tertiary nitrogen atom in the molecule, was shown to produce a central effect in a dose of 20 mg/kg--1/50 LD50--in contrast to diproxime in a dose of 3 mg/kg, containing a quarternary nitrogen atom, under intoxication of albino rats and rabbits with dimethyl-dichlorynylphosphate. This effect was confirmed by the restortion of the cholinesterase activity in different parts of the rabbit brain, by the normalization of the EEGand of the functional stateof motor neurons of the rat spinal cord.


[Effect of lithium chloride on the rat hypothalamus neurosecretory system]. Methods of quantitative cytochemical analysis were applied to the study of the reaction of the hypothalamohypophysial neurosecretory system (HHNS) to single and course administrations of lithium chloride (in doses of 200 mg/kg). Reaction of the HHNS proved to depend directly on the amount of lithium administered and was characteriaed by the activation of the synthesis and elemination of the neurosecretion with a single administration on the preparation, or depression of the hormonopoiesis in the hypothalamus and exhaustion of the neurosecretion stores in the neurohypophysis in its course application. During the restoration (7 to 30 days after stopping the drug administration) the state of the HHNS gradually approached the initial level. The authors came to the conclusion that the changes in the central mechanisms of the neuro-endocrine regulation at the hypothalamic level caused by lithium were significant in the pathogenesis of the side-action of its salts


[Effect of bacterial polysaccharide on the quantity of rosette-forming cells in mice with decreased immunologic reactivity]. The influence of bacterial polysaccharide on the amount of the rosette-forming cells (RFC) in mice with decreased immunological reactivity (irradiation in a dose of 400 rad, gamma-rays, administration of cyclophosphamide in a dose of 200 mg/kg) was studied. Bacterial polysaccharide increased the amount of RFC in the intact, immunized and irradiated animals. However, polysaccharide produced no stimulating action on the RFC formation in mice treated with cyclophosphamide this confirming different nature of depression of the immunological reactivity under the effect of irradiation and cyclophosphamide.


[Kinetics and properties of a cortisol-resistant population of lymphocytes from lymph nodes of guinea pigs sensitized to protein]. Lymphocytes from the cervical lymph nodes of guinea pigs were incubated in medium 199 in the presence of cortizol in a concentration of 20 and 100 microng% for 24 hours. A determination was made of the lymphocyte survival and cortizol metabolism by them, and also (cytophotometrically) the nucleic acid content. In the intact and the sesitized guinea pigs progesterone in a concentration of 10-5 inhibited both the lytic action of coritizol and its metabolism There was observed a marked reduction of cortizol meta bolism by the lymphocytes from the 6th day after the sensitization, which was restored only by the 90th day. The cortizol-resistant lymphocyte population increased on the 17th--30th day. In a concentration of 100 microng% cortizol reduced the nucleic acid content in the lymphocytes of both the intact guinea pigs and sensitized ones on the 17th--30th day, when the cortizol-resistant population increased.


[Post-traumatic regeneration of rat skin with stimulation under conditions of gravitational stress]. Albino rats were subjected to multiple gravitation stress (11units) before infliction wounds. A marked vascular reaction was noted in the wound contents at the early observation period. The appearance and differentiation of granulation and epidermis proliferation periods were delayed. Healing the wound occurred on the 30th day (on the 15th--18th day in controls). Administration of the skin tissue extract (prepared by Filatory's method) under these conditions, simultaneously with the wound infliction and up to their healing sharply reduced the vascular reaction, accelerated the granulation differentiation and the epithelialization of the wound; in respect to the character and the periods of tissue differentiation development the restoration process thus approached the course of the post-traumatic skin regeneration under usual conditions.


[Quantitative changes in myoneural synapses and capillaries under the influence of physical stress]. Experiments conducted on young male rats showed that dosaged muscular training with its gradual increase in the course of one month, promoted an increase in the area of both the neuro-muscular synapses and metabolic surface of capillaries in the region occupied by them. These quantitative changes are the morphological equivalent of increasing the activity of the neuro-muscular apparatus in physical exertion.


[Means of experimentally reproducing the vertebral artery syndrome]. The authors suggest a method of reproducing the syndrome of vertebral artery in a chronic experiment on dogs. Two horse-shoe electrodes connected with the wires exteriorised to the posterior surface of the neck are introduced and fixed under general anesthesia at the selected level into the vertebral artery. Rheographic and thermometric shifts occurring in response to the electrode stimulation and to dosaged electrical stimulation were studied.


[Effect of tetraethylammonium on electrophysiologic properties of pulmonary artery smooth muscle cells]. Using the microelectrode technique combined with sucrose gap method it was shown that in the tetraethylammonium (TEA) solution a pulmonalis muscle cells exhibited spontaneous or elicited action potentials caused by depolarizing current. It is suggested that the appearance of the electrical activity due to inhibition with TEA of the voltage-dependent delayed potassium current, early activation of which in normal Krebs solution prevented the action potential development. Ca ions took part in the action potential generation because it was inhibited by Mn ions. Besides, delayed potassium current inhibition, TEA showed nonspecific action on the arterial muscle cells expressed in the following: 1) depolarizing action accompanied by increase of the membrane resistance; 2) stimulation of the extracellular calcium entry into the muscle cells followed by tonic muscle contraction; 3) establishment of coupling between the contraction and the resting potential.


[Changes in the rate of metabolic clearance of cortisol in dogs having sustained terminal states]. At the early post-reanimation period, after a 15-minute circulatory arrest a decrease of the metabolic clearance rate of 17-oxycorticosteroids (17-OCS) was revealed in dogs most pronounced in those which later died. This reduction was chiefly determined by the fall in the splanchnic organ clearance of plasma 17-OCS, and was connected apparently with the circulatory disorders in the organism.


[Changes in several indices of gas exchange in dogs during the initial stage of Cannon's traumatic shock]. In experiments reproducing traumatic shock according to Cannon on 35 dogs it was shown that metabolic acidosis developed in shock against the background of sharply elevated oxgen consumption at the very beginning of injury, when the arterial pressure exceeds considerably the inital level. In traumatic shock the brain is under the most favourable conditions of gas exchange and the skeletal musculature of the extremities--under the worst ones. It was concluded that in severe trauma, despite the strain of respiratory and cardiovascular system function the tissues of the brain and the skeletal muscles failed to obtain an adequate O2 quantity because of their sharply increases needs in oxygen, as well as of hemodynamic disturbances.


[Age and characteristics of cholesterol biosynthesis in rat liver under normal conditions and during atherogenic loading]. Intraperitoneal injection of C14CH3COONa to normal rats aged 6--8 and 28--32 months revealed a slower dynamics of cholesterol biosynthesis in the liver of old rats at the maximum of the tracer incorporation was lower than in the young ones. Atherogenic diet (0.25 g of cholesterol per 100 g of animal weight for a period of 20 days) was accompanied by an increase in the total cholesterol content and depressio of its biosynthesis in the liver, more pronounced in the young rats. Continued cholesterol administration caused further depression of its biosynthesis, most pronounced (in this case) in the old animals.


[Fat and carbohydrate absorption in an allogenic small intestine transplant]. The authors present the results of study of the absorptive function of the allogeneic small intestine (with the aid of D-xylose load and electron-microscopic study of the neutral lipid transport in the wall of the intestine). An unusual increase of D-xylose absorption against the background of structural changes in the intestinal wall and disturbance of lipid transport was shown.


[Interaction of renal transport of cardiotrast, glucose and urates in dogs]. Interaction of renal cardiotrast, glucose and urate transport was investigated in dogs in chronic experiments. There was no alteration in the maximum secretion of cardiotrast and in the malximum glucose reabsorption during simultaneous injection of cardiotrast and glucose. It was also shown that with the maximum saturation of the renal secretory and reabsorption transport there was no significant change in the urate excretion. The data obtained pointed to a possibility of combined administration of cardiotrast and glucose solutions with simultaneous determination of values of maximum cardiotrast secretion, maximum glucose reabsorption and urate excretion.


[Presence of aggregated immunoglobulins on the surface of rapidly dividing antigen-binding lymphocytes]. Rosette-forming cells containing on their surface aggregated immunoglobulins appeared in the fraction of small lymphocytes of the spleen in primary immune response of mice to sheep erythrocytes. These cells effectively incorporate thymidine and can be eliminated in vivo as a result of administration to mice of high doses of tritium labeled base. A conclusion is drawn that the rapidly dividing lymphocytes specifically binding the antigen are characterized by the presence of aggregated immunoglobulins on their surface.


[Kinetics and properties of a cortisol-resistant population of lymphocytes from the lymph nodes of guinea pigs with experimental allergic encephalomyelitis]. Lymphocytes from the cervical lymph nodes of guinea pigs were incubated in medium 199 in the presence of cortizol in a concentration of 20 and 100 microng% for 24 hours. A determination was made of the lymphocyte survival and cortizol metabolism by them, and also (cytophotometrically) the nucleic acid content. There proved to be a marked reduction of cortizol metabolism by the lymphocytes from the 6th day after the administration of the encephalytogenic mixture and a marked increase of the cortizol-resistant population of lymphocytes in the guinea pigs with encephalomyelitis, and on the 17th--30th day after the administration of a complete stimulant. In a concentration of 100 microng% cortizol reduced the nucleic acid content in the lymphocytes of the intact animals, but had no influence upon the lymphocytes of both experimental groups of guinea pigs at the period of a marked increase of the cortizol-resistant population. Progesteron decreased the lympholytic action of cortizol and the metabolism of this hormone by the lymphocytes of intact guinea pigs. The capacity of progesteron to decrease the lympholytic action of cortizol was weakened in guinea pigs with encephalomyelitis and in the animals given the stimulant.


[Interacetion of myeloid and stromal bone marrow elements in acute experimental aplasia]. Acute hypoplasia of the hemopoiesis was induced in guinea pigs by the administration of vynbalstin  in  a dose of 0.1 mg per 100 g of weight, intraperitoneally, once or twice at an interval of 7 days. Myelokariocyte count, the concentration (per 10(5) of myelokariocytes) and the total amount of the fibroblast precursors was determined in the femur by the fibroblast colony method. After the administration of the cytostatic, simultaneously with the reduction of the myelokariocyte count there was noted a change in the concentration of the stromal precursors and a fall of the total precursor count per femur. It is supposed that the bone marrow reaction under hypoplasia conditions was caused by the interaction of the myeloid and stromal elements.


[Kinetics of bone marrow cells under conditions of fractional x-irradiation]. A study was made of the damaging effect of fractionating X-irradiation (12 rad a day, up to the sum total doses of 250, 500, 750, 1000 and 1500 rad) on the hemopoiesis in guinea pigs. A phasic character of the changes in the erythro- and myelopoiesis during the damage was revealed. The first phase was attented by the activation of the proliferation processes expressed in the increase of mitotic index, reduced duration of the mitotic cycle of the cells belonging to the erythroid and the myeloid series and their accelerated differentiation, this stipulating for a sufficient entrance of the cells into the blood flow and maintaining the erythrocyte and leukocyte content in the peripheral blood approaching the normal level. A reduction of the proliferative processes in the bone marrow was observed during the second phase; these were also a reduction of the mitotic index, prolongation of the mitotic cycle and of the rate cell diferentiation of the erythroid and myeloid series, this being accompanied by anemia and leukopenia in the peripheral blood.


[Determining circulatory minute volume by the rebreathing method]. Possibility of applying the rebreathing method for estimating the cardiac output in case when ventilation did not correlate with the lung blood flow is discussed. pCO2 of mixed venous blood was determined by its equilibration with pCO2 of the alveolar air by the rebreathing method. Gas mixture containing almost as much CO2 as in venous blood was created by the patient by rebreathing into a bag, 2--3 litres in volume, filled with oxygen. By the differences in the shape of the capnogram the ununiformity in the distribution of ventilation in respect to the cardiac output was judged. In the absence of uniformity pCO2 of the arterial blood was measured. This correction allows evaluation of cardiac output in patients with cardiac and lung diseases. A possibility of using standard nomograms for evaluating CO2 store in the arterial and venous blood in case of serious disturbances of the acid-base balance is discussed.


[Stereologic method of determining the volumetric density of the arterial bed of the myocardium in histologic sections]. The volumetric density of the intramyocardial arteries proved to be equal to the sum of their volumetric densities obtained by the planimetric measurements on three interperpendicular histological sections. To avoid systematic errors only the vessels in which the ratio of the short (D) and long (L) diameters of the sections was not below (see article) greater than or equal to 0.707 should be subjected to planimetry. Examples of estimation of the volumetric density of human intramyocardial arteries are given. The volumetric density of the intramyocardial arteries was not equal in different parts of the myocardium.


[Adrenosensitive neurons of the myenteric (Auerbach's) plexus]. Experiments were conducted on the myenteral plexus of the isolated stips of the small and large intestine; the presence of adrenosensitive cells which reacted to the application of different adrenaline (A) and noradrenaline (NA) concentrations by a distinct acceleration of the activity rhythm was demonstrated. NA with a greater range of action than A (from 10(-9) to 10(-5 g/ml) has the most marked effect. Introduction into the irrigating solution of phentholamine eliminated the mentioned effects in the majority of cases. "Silent" neurons without any spontaneous activity responded to the A and NA administration along with those possessing this activiy. As supposed, catecholamines could take a direct part in the modulation of the processes realized by the ganglionic neurons of the myenteral plexus.


[Functional and structural changes in the adrenal cortex of rabbits under conditions of chronic inflammation of the prostate gland]. Investigation of the state of the rabbit adrenal cortex under conditions of depression of the incretory activity of the testicles resulting from chronic inflammation of the prostate showed progressive hyperplasia of the reticular zone of the adrenal cortex; as to the glomerular zone, it failed to display any marked pathological changes, and the fascicular zone demonstrated some signs of hypoplasia. Thus, the normal or elevated androgen excretion observed in the experimental male rabbits, was provided by an intensified activity of the reticular zone of the adrenal cortex, despite a decrease in testosterone biosynthesis in the testes.


[Role of glycosaminoglycans and proteoglycans in erythrocyte aggregation and adhesion]. The action of hyaluronate potassium (HUK) and of protein chondroitin-4-sulphate potassium (PCHSK) on the aggregation and adhesion of rabbit erythrocytes suspended in physiological saline was studied. It was found that the capacity of HUK and PCHSK to produce an unspecific and reversible aggregation of erythrocytes was connected with the formation by these biopolymeres (in solutions) of complex structures of osmotic cell type and molecular sieves, displacing cells from the space occupied by them and concentrating them in a maximally limited volume. Different heparin fractions producing no such structures in solutions did not induce formation of such individual clear-cut erythrocyte-aggregations, but inhibited the aggregating action of HUK and PCHSK when the concentration of these biopolymeres were inadequate for the complete erythrocyte aggregation. Probably, the aggregating action of HUK and PCHSK necessary for adhesion served as one of the universal biological functions expressed not only towards the erythrocytes, but also towards the other cells and different tissue structural elements.


[Homocytotrophic IgG1- and IgE-antibodies and passive cutaneous anaphylaxis in mice of different strains]. Investigations on mice of 9 strains of different H-2 genotypes demonstrated that predisposition to anaphylaxis at the stage of the IgG1- and IgE-antibody formation, skin sensitivity to passive anaphylaxis and histamine were unrelated traits. The interaction of these factors with one another and with the other factors formed a general predisposition to the immediate allergy.


[Specific inhibition of macrophage adherence in animals with post-traumatic autoallergic aspermatogenesis]. The macrophage adherence inhibition was studied in the peritoneal macrophages of guinea pigs with induced posttraumatic aspermatogenesis at various periods after the testis injury. Reliable peritoneal macrophages adherence inhibition was observed in the presence of the testis-specific antigen. The adherence inhibition reflected the autoimmune character of the testis affection.


[Activity of coenzyme A and N-acetyltransferase during tumor growth]. The activity of acetylation of sulphadimezine in C57B1/He mice with the low spontaneous tumour incidence was significantly lower than in the C3H/Sn mice with high spontaneous tumour incidence. The development of malignant melanoma B-16 in the C57B1/He mice led to increase in the activity of the sulphadimezine acetylation. Along with the previously obtained information, these data indicated the relationship between the development of tumour process and changes in the activity of the enzyme N-acetyltransferase. No difference in the acetylation of the sulphaylamide was found in the same groups of mice; this points to the absence of any differences in the coenzyme A level.


[Neurotrophic interaction of spinal cord ganglia with different tissues]. Spinal ganglia L5-L6 together with mesocolon (innervated from these ganlia) and tongue epithelium were transplanted into the anterior chamber of the cat eye. In 2 months survival of some of the sensory neurons and intensive regeneration of their nerve fibers was observed. At the same time the mesocolon tissues with the mechanoreceptors (Pacinian corpuscles) were found to survive. Destruction of the tongue epithelium was revealed. The trophic effect of definite sensory ganglia on the tissue corresponding to them provided structural intactness of this tissue and of its receptor apparatus. It is suggested that the metabolic conformity of the tissue and the source of its innervation is necessary for the tissue survival.


[Dynamics of DNA concentration in the nuclei of rat cardiac muscle cells in experimental myocardial infarct]. The content of nuclear DNA was determined microspectrophotometrically in rat cardiac myocyte nuclei at various intervals after the onset of experimental myocardial infarction. In the intact rat heart 1.5 to 1.8% of myocyte nuclei contained tetraploid DNA. Myocardial infarction activated the process of polyploidization in the nuclei of the myocytes particularly in those surrounding the lesion. This process was most intensive during the first week. At later intervals there was an evidence of continuously increasing polyploidization.


[Cytopharmacologic effect of using polyvinylpyridine-N-oxide in experimental silicosis]. Methods of scanning, transmission electron microscopy and cytochemistry were applied to the study of the development of experimental silicosis against the background of polyvinylpyridine-N-oxide administration. The majority of the macrophages retained their functional activity and realized quartz phagocytosis, eliminating it through the airway. Bringing the proteins on the cell surface in the fibroblasts was delayed, and formation of collagen fibers decreased. Application of the polymere prevented development of fibrosis of the lungs.


Variations in lymphocyte counts four hours after administration of hydrocortisone in patients with chronic lymphocytic leukemia. The peripheral lymphocyte count and the number of large unstained cells (LUC) were investigated prior to and 4 hr after a single intravenous injection of 400 mg of hydrocortisone in 23 controls and 51 patients with lymphoid disorders (43 chronic lymphocytic leukemia, 3 cases of Waldenström macroglobulinemia, 2 hairy cell leukemias, 1 Sézary syndrome, and 2 cases of infectious mononucleosis). A reduction in both the peripheral lymphocyte counts and the number of LUC was observed in all normal controls, the mean decrease being 54% and greater than 60%, respectively, with differences according to age. In chronic lymphocytic leukemia (CLL), the peripheral lymphocyte count showed a variable response: decrease, no change, or increase. A correlation was shown to exist between a decrease in peripheral lymphocyte counts and anatomical-clinical staging: patients with involvement restricted to blood and bone marrow very often exhibited a drop in their peripheral lymphocyte count (p less than 0.01). In addition, the percentage of circulating T lymphocytes was higher (54%) in CLL patients whose peripheral lymphocyte count dropped than in other CLL patients (p less than 0.001).


Detection of sickle alpha- or beta0-thalassemia by studies of globin biosynthesis. Globin synthesis studies are useful in the analysis of thalassemia syndromes. We have applied globin synthesis and free alpha-chain pool studies of peripheral blood to characterize hematologic disorders where alpha- or beta-thalassemia was present in combination with HbS or HbC. In 60 non-thalassemic controls, the beta/alpha specific activity ratio was 1.01 +/- 0.06 (SD). In three patients with HbS-beta0-thalassemia, the (betas + gamma)/alpha ratios were 0.48-.067. In four patients with HbSS-alpha-thalassemia, the (BETAS/ALPHA RATIO was 1.26 +/- 0.18 (1.13-1.53). The radioactive free alpha-chain pool in three patients with HbS-beta0-thalassemia was elevated (35.1%-53.0%), while three patients with HbSS-alpha-thalassemia had decreased free radioactive alpha-chain pools (3.2%-6.4%); both were significantly different from the mean (15.1% +/- 2.6%) of the 17 iron-sufficient controls. Simultaneous studies of the fraction of newly synthesized alpha chain contained in the free alpha-chain pool in peripheral blood and bone marrow demonstrated that this fraction was larger in peripheral blood than in marrow, and that the differences between thalassemia patients and controls previously found in bone marrow using these methods were also present in peripheral blood. The results indicate that even when family studies are not possible, patients with HbS in combination with alpha- or beta0-thalassemia can be differentiated from those with homozygous sickle cell disease by globin synthesis and free alpha-chain pool studies using peripheral blood.