Extraction method for preparing pyridylamino sugar derivatives and application to porcine gastric mucus glycoprotein analysis

For the sensitive detection of free sugars and oligosaccharides, the use of their pyridylamino derivatives has now found general acceptance. To remove excess 2-aminopyridine from this derivative in a reaction mixture, gel filtration and ion-exchange chromatography were conducted. It was found in the present study that contaminated 2-aminopyridine could be selectively removed from the reaction mixture by adjusting the pH with saturated sodium bicarbonate at above 8.5 followed by extraction with benzene. By using this method, fewer purification steps and less time are required, with minimum loss of pyridylamino sugar derivatives.     

Arginase as an inhibitory principle in liver plasma membranes arresting the growth of various mammalian cells in vitro

Plasma membranes prepared from rat livers inhibited the in vitro growth of various mammalian cells including hepatoma cells in a concentration-dependent manner, showing an almost complete arrest of cell growth at 0.1 mg protein/ml. Some of these cells tested, i.e., leukemia (L1210 and P388) and myeloma (P₃-NS-1/1-Ag4-1) cells, were labile in the presence of plasma membranes (losing the viability), and CHO (Chinese hamster ovary) cells became round without detaching from the substratum. The culture medium preincubated with liver plasma membranes no longer supported the growth of hepatoma cells (AH13 and AH66F). However, the ‘conditioned’ medium supplemented with l-arginine, supported the growth of the cells. Moreover, the addition of l-ornithine to the cultures containing plasma membranes markedly reduced the inhibitory effect of plasma membranes. The plasma membrane preparations were found to possess considerable arginase activity. These results seem to indicate the possible involvement of arginase in the inhibition of cell growth by liver plasma membranes.     

Ultrastructural and biochemical identification of con A receptors in the desmosome

Correlated ultrastructural and biochemical methods were used to identify and localize Concanavalin A (Con A) receptors in the desmosomes of bovine epidermis. Specific carbohydrate residues were labeled with ferritin-Con A in thin sections of tissue embedded in a hydrophilic resin. Quantitative mapping of ferritin distribution in labeled desmosomes revealed that Con A receptors are localized in the intercellular zone and concentrated along the desmosomal midline or central dense stratum. Labeling was almost entirely absent when sections were treated with ferritin-Con A in the presence of 0.1 M α-methyl mannoside, a hapten-inhibitor of Con A. “Whole” desmosomes and desmosomal intercellular regions (desmosomal “cores”) were purified from bovine muzzle epidermis. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis reveals a limited number of major desmosomal protein constituents. Certain of these are glycoproteins and are greatly enriched in the core fraction. Almost all the desmosomal glycoproteins are intensely labeled when electrophoretic gels of whole desmosome or core fractions are exposed to fluorescent Concanavalin A.     

Ribosomal resistance of an istamycin producer, Streptomycestenjimariensis, to aminoglycoside antibiotics

$\text{Streptomyces}\text{tenjimariensis}$ SS-939 was resistant to its own aminoglycoside antibiotics, istamycins, as well as kanamycin A, neamine, ribostamycin and butirosin A, but was susceptible to neomycin B, lividomycin A and streptomycin. This resistance to these antibiotics was found to be due to ribosomes of the strain.     

Replicative bypass repair of ultraviolet damage to DNA of mammalian cells: Caffeine sensitive and caffeine resistant mechanisms

Replicative bypass repair of UV damage to DNA was studied in wide variety of human, mouse and hamster cells in culture. Survival curve analysis revealed that in established cell lines (mouse L, Chinese hamster V79, HeLa S3 and SV40-transformed xeroderma pigmentosum (XP)), post-UV caffeine treatment potentiated cell killing by reducing the extrapolation number and mean lethal UV fluence (Do). In the Do reduction as the result of random inactivation by caffeine of sensitive repair there were marked clonal differences among such cell lines, V79 being most sensitive to caffeine potentiation. However, other diploid cell lines (normal human, excision-defective XP and Syrian hamster) exhibited no obvious reduction in Do by caffeine. In parallel, alkaline sucrose sedimentation results showed that the conversion of initially smaller segments of DNA synthetized after irradiation with 10 J/m² to high-molecular-weight DNA was inhibited by caffeine in transformed XP cells, but not in the diploid human cell lines. Exceptionall, diploid XP variants had a retarded ability of bypass repair which was drastically prevented by caffeine, so that caffeine enhanced the lethal effect of UV. Neutral CsCl study on the bypass repair mechanism by use of bromodeoxyuridine for DNA synthesis on damaged template suggests that the pyrimidine dimer acts as a block to replication and subsequently it is circumvented presumably by a new process involving replicative bypassing following strand displacement, rather than by gap-filling de novo. This mechanism worked similarly in normal and XP cells, whether or not caffeine was present, indicating that excision of dimer is not always necessary. However, replicative became defective in XP variant and transformed XP cells when caffeine was present. It appears, therefore, that the replicative bypass repair process is either caffeine resistant or sensitive, depending on the cell type used, but not necessarily on the excision repair capability.     

Effect of disinfectants on variola virus in cell culture.

Twenty kinds of disinfectants were examined for ability to inactivate variola virus. Cytopathic effect and plaque formation on monolayer cultures of an established monkey kidney cell line were used as indicators of virus inactivation. A micromethod using microplate cultures, and not requiring a CO2 incubator, was adopted. The procedures were straightforward, showing good reproducibility. Among the compounds tested, several were found to be superior because of the minimum concentrations required for complete inactivation of virus. The purified viruses were shown to be more sensitive to the compounds than were the crude samples. The virus inactivation kinetics curves were determined by plaque counting. The usefulness of this method for quantitative analysis of disinfecting effect is suggested.     

Detection of SO2 at the ppm Level with Localized Surface Plasmon Resonance (LSPR) Sensing

Plasmonics - Detection and monitoring of SO2 is important because it is a representative toxic gas in the atmospheric environment that is emitted from industrial and natural processes. Localized...     

MicroRNA-30c attenuates fibrosis progression and vascular dysfunction in systemic sclerosis model mice

Molecular Biology Reports - Systemic sclerosis (SSc) is characterized by peripheral circulatory disturbance and fibrosis in skin and visceral organs. We recently demonstrated that...