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Synthetic zeolites are found to be effective catalysts for ring transformation of heterocycles. Furan reacts with ammonia over BaY to form pyrrole in 100% selectivity at 330°C. Tetrahydrofuran is converted to pyrrolidine in 70% selectivity over HY and MgY at 320°C, and γ-butyrolactone is converted to 2-pyrrolidone in 80% selectivity over CuY.

Inhibitors of protein synthesis capable of differential effects on nascent peptide synthesis on membrane-bound and free polyribosomes were employed to investigate the structure and function of cellular membranes of liver. The formation of membranous whorls in the cytoplasm and distension of nuclear membranes were induced by inhibitors of protein synthesis (i.e., cycloheximide and emetine) which predominantly interfere with nascent peptide synthesis on membrane-bound polyribosomes in situ. Other inhibitors of protein synthesis such as puromycin and fusidic acid, which inhibit nascent peptide synthesis on both free and membrane-bound polyribosomes, and chloramphenicol, which inhibits mitochondrial protein synthesis, did not induce these alterations. Cycloheximide, puromycin, and chloramphenicol produce some common cellular lesions as reflected by similar alterations in morphology, such as swelling of mitochondria, degranulation of rough endoplasmic reticulum, and aggregation of free ribosomes. The process of whorl formation in the cytoplasm, the incorporation of [3H]leucine and of [3H]choline into endoplasmic reticulum and the total NADPH-cytochrome c reductase activity of the endoplasmic reticulum were determined. During maximum formation of membranous whorls, [3H]leucine incorporation into cytoplasmic membranes was inhibited, while [3H]choline incorporation into these structures was increased; maximum inhibition of protein synthesis and stimulation of choline incorporation into endoplasmic reticulum, however, preceded whorl formation. Cycloheximide decreased the activity of NADPH-cytochrome c reductase of rough endoplasmic reticulum, but increased NADPH-cytochrome c reductase activity of smooth endoplasmic reticulum. In addition, cycloheximide decreased the content of hemoprotein in both the microsomal and mitochondrial fractions of rat liver, and the activities of mixed function oxidase and of oxidative phosphorylation were impaired to different degrees. Succinate-stimulated microsomal oxidation was also inhibited. The possible mechanisms involved in the formation of membranous whorls, as well as their functions, are discussed.

In the design method proposed, say the authors, the effect of changing any of the variables pertaining to filtration efficiency can be evaluated with satisfactory precision. Data on filters of various designs, treating different kinds of raw supplies, are presented and discussed.

The characteristics of the inducible galactose system in Saccharomyces cerevisiaewere studied by using the nonmetabolized galactose analogues, l-arabinose and d-fucose, and galactokinaseless and transportless mutants. Induced wild-type cells transport l-arabinose by facilitated diffusion. Transportless cells transport neither galactose nor l-arabinose above the noninduced rate, whereas galactokinaseless cells transport galactose l-arabinose and d-fucose by facilitated diffusion. Determination of unidirectional rate of 14C-labeled galactose uptake by preloaded galactokinaseless cells, containing a large unlabeled free-galactose pool, showed that the rate of galactose uptake by facilitated diffusion is greater than the rate of galactose metabolism at similar external galactose concentrations.

A morphological mutant of Escherichia coliK-12 that grows as round cells at 30, 37, or 42 C in a variety of complex and synthetic media has been isolated and characterized. The gene concerned, designated rodA, has been shown to be on the chromosome between the purEand pyrCloci and to be located at about minute 15. The rodAgene has been found to be co-transducible with the lipgene at a frequency of 95%. The rodAmutant showed an increased resistance to ultraviolet irradiation and a changed sensitivity to drugs. The resistance to ultraviolet irradiation and mitomycin C appears to be co-transducible with the rodAgene.

Abrin and ricin are highly toxic proteins isolated and crystallized from Abrus precatorius1and Ricinus communis respectively2–4. The LD50s of abrin and ricin are 0.020 0.012 mg/kg body weight of mice respectively. Both have a molecular weight of 65,000, but a different chemical structure as judged by the analysis of N and C terminal amino-acid residues. For abrin these are leucine5, while the N-termini of ricin are alanine and isoleucine, and the C-termini are phenylalanine and serine2,6. The biological activities of the two proteins are alike; both cause similar toxic symptoms and have no effect on mitochondrial respiration7,8. The inhibitory effect of abrin and ricin on Ehrlich ascites tumour has been demonstrated by simultaneous injection of a sublethal dose with the tumour cells. Total inhibition of tumour growth in mice was demonstrated by measurements of body weight and total cell numbers in the peritoneal cavity. The therapeutic index of abrin was found to be 4. These inhibitory effects can be eliminated by heating the phytotoxin solution at 100° C for 30 min9,10, which indicates that the anti-tumour activity of phytotoxins is due to protein.

The investigations were carried out on photovoltaic effects of Ge films vacuum-deposited on glass substrate at an oblique angle of incidence of 45°. By introducing air slowly to the vacuum system the change in photovoltage of the film with the pressure was measured. By illumination through a band-pass filter (0.3µ???0.4µ), the photovoltage reversed its sign as the pressure was increased. The sign was changed from negative to positive in case of the illumination from frontside of the substrate, while in case of the illumination from backside, it was changed from positive to negative. The magnitude of the photovoltage increased remarkably in both cases as the pressure approached atmospheric one. On the other hand, when a short-cut filter (0.69µ??) was used, the photovoltages increased with the pressure but their polarities were always positive regardless of the direction of the illumination. Spectral sensitivity of photovoltage in air was also measured. Only in case of the illumination from backside of the substrate, the photovoltage showed negative polarity in the region of wavelength shorter than 0.5µ. These changes in photovoltages with the pressure are ascribed to those of surface recombination velocities of the film due to gas adsorption. The origin of these photovoltages is discussed on the basis of the Dember effect which arises from the difference between electron and hole mobilities.