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Bisphenol E decomposes in high-temperature liquid water to form 4-vinylphenol plus phenol as primary products. 4-Vinylphenol can react further to form 4-ethylphenol and, presumably, vinylphenol oligomers. Phenol is always the major product within the parameter space (250-350 °C) explored experimentally. The decomposition, which follows global first-order kinetics, is essentially complete at 350 °C after 60 min. We developed a quantitative kinetics model that provides a faithful correlation of the effects of temperature and reaction time on the yields of unreacted bisphenol E and the reaction products.

The humanized monoclonal antibody maytansinoid conjugate, cantuzumab mertansine (huC242-DM1) that contains on average three to four linked drug molecules per antibody molecule was evaluated in CD-1 mice for its pharmacokinetic behavior and tissue distribution, and the results were compared with those of the free antibody huC242. The pharmacokinetics in blood were similar for (125)I-labeled conjugate and antibody with terminal half-lives of 154 and 156 h, respectively. Pharmacokinetic analysis using an enzyme-linked immunosorbent assay (ELISA) method, which measures intact conjugate in plasma samples revealed a faster clearance for the conjugate corresponding to a half-life of 42.2 h. This faster clearance is explained as the result of clearance from circulation and concomitant clearance of drug from circulating conjugate through linker cleavage. An antibody-specific ELISA allowed the determination of the clearance rate of the antibody component from circulation. The drug clearance rate from circulating conjugate was then calculated as the difference between the clearance of the conjugate and the clearance of the antibody component and found to be about three times that of the antibody component. The above results were confirmed with a conjugate, huC242-[(3)H]DM1, where the linked DM1 drugs carried a stable tritium label. Tissue distribution studies with (125)I-labeled conjugate and antibody showed antibody-like behavior for the conjugate; the antibody of the conjugate did not distribute or bind significantly to any solid tissue.

The article discusses different scenarios where students from different grades received Orff Schulwerk instruction without the use of barred instruments. It notes that the results of learning through Orff Schulwerk goes beyond the use of instruments, and advocates the use of body sounds, gestures, and voice as the basic foundation of learning and expressing music. It explains the five areas of learning activity proposed by Orff-Schulwerk Forum founder, Hermann Regner.

Deoxycoformycin-resistant rat hepatoma cells exhibit up to 300-fold increase in adenosine deaminase activity compared to the sensitive parental cells. In order to determine the basis of the increased enzyme activity in deoxycoformycin-resistant cells, adenosine deaminase was purified from rat liver and deoxycoformycin-sensitive and -resistant cells. Physical, kinetic, and immunological properties of the purified enzymes were compared. Purified adenosine deaminase from all sources was found to be a monomer with an Mr approximately 45,000. In addition, the purified enzymes had a similar isozyme pattern in nondenaturing polyacrylamide gels. Km values for adenosine and Ki values for deoxycoformycin did not differ among the purified enzymes. By double diffusion analysis and quantitative immunoprecipitation, the purified enzymes were found to be immunologically indistinguishable. These data indicate that deoxycoformycin-resistant rat hepatoma cells produce increased amounts of adenosine deaminase protein which results in increased enzymatic activity.

Deoxycoformycin-resistant rat hepatoma cells exhibit up to a 2000-fold increase in adenosine deaminase activity compared to the sensitive parental cells. The increased enzyme activity in these cells is accompanied by similar increases in 1) the amount of adenosine deaminase protein, 2) the relative rate of adenosine deaminase synthesis in vivo, and 3) adenosine deaminase mRNA activity. To further investigate the mechanism(s) responsible for the overproduction of adenosine deaminase in these cells, we have isolated a recombinant plasmid containing a 1.4-kilobase insert complementary to at least part of the adenosine deaminase mRNA. Using this cDNA as a specific hybridization probe, all deoxycoformycin-resistant variants were shown to have increased amounts of adenosine deaminase mRNA and gene sequences. The relative increase in the level of mRNA and gene copy number was similar to the relative increase in enzyme activity for most resistant cell lines. However, the degree of adenosine deaminase gene amplification in one deoxycoformycin-resistant cell line (6-10-200) was 3-4-fold less than the relative increase in adenosine deaminase mRNA. These results indicate that the increased adenosine deaminase activity in deoxycoformycin-resistant rat hepatoma cells is due in large part, but not exclusively, to gene amplification.

Two independently selected series of rat hepatoma cell lines resistant to the drug deoxycoformycin (dCF) were analyzed karyotypically. Several forms of homogeneously staining regions (HSRs) were present on metaphase chromosomes of these cells. In some instances HSRs comprised nearly an entire chromosome, which are among the largest chromosomes in the karyotype. Stable resistance to dCF is acquired in rat cells by overproduction of the enzyme adenosine deaminase (ADA) as a result of amplification of ADA gene sequences. We have localized the amplified ADA gene sequences to HSRs on metaphase chromosomes from both series of dCF-resistant cell lines by in situ hybridization. Based upon the number of ADA gene sequences present and the lengths of the HSRs, we have estimated the size of the amplified unit to range from 450 to 1,000 kb.

Rat hepatoma cells amplified for adenosine deaminase (ADA) gene sequences show the amplified DNA on large, homogeneously staining regions (HSRs). The amplified cells are stable in the absence of selection for 12 mo without loss of ADA activity or gene sequences. However, in hybrids formed between an amplified cell line with a prominent HSR and a nonamplified cell line, rapid loss of ADA activity, as well as gene sequences, occurs. Karyotype analyses of the hybrids indicate that the HSR structures are no longer visible in a large percentage of the hybrid metaphase spreads and appear to have been replaced by DNA structures that resemble double minutes. Our data provide evidence that (1) the extent of the breakdown of the HSR in the hybrids may be affected by the presence of an active adenosine kinase or the level of ATP in the cells and (2) additional unidentified factors are present in the hybrids that affect the integrity of the HSR structure. There is no evidence for a specific transacting factor in nonamplified cells that regulates gene amplification.

Wild-type and nonchemotactic mutant strains of Rhizobium meliloti were tested for attraction to localized sites on alfalfa roots and for attraction to numerous small molecules, including sugars, amino acids, and two fractions derived from alfalfa root extracts. Four strains (carrying mutations che-6, che-11, che-12, and che-26) lost all responses and were classified as generally nonchemotactic mutants. One strain (carrying mutation che-7) lost responses to a group of structurally unrelated amino acids but retained all other responses and was classified as a putative sensory transducer mutant. Two strains (carrying mutations che-1 and che-3) lost responses to all the amino acids and sugars tested but retained normal responses to localized sites on roots and to the root fractions. These two mutant strains could not be classified according to the generally accepted model for a sensory pathway, derived from studies of enteric bacteria, and provided evidence for a dual chemotaxis pathway in R. meliloti.

The basis for the increased adenosine deaminase activity in deoxycoformycin-resistant rat hepatoma cells was investigated. Three variant cell lines with different levels of adenosine deaminase activity showed increases in the relative rate of synthesis of the enzyme in vivo. No difference in the rate of degradation of the enzyme was seen between the parental cell line and one variant cell line which exhibits a 180-fold increase in adenosine deaminase activity. Polysomal RNA isolated from this variant exhibited a 175-fold increase in the ability to direct the synthesis of adenosine deaminase in vitro.

Four enzymes involved in ribonucleoside and deoxyribonucleoside catabolism (deoxyribose-5-P aldolase, thymidine phosphorylase, phosphodeoxyribomutase, and purine nucleoside phosphorylase) are coded for by four closely linked structural genes on the Salmonellachromosome. The genetic order of these genes is (deoC-deoA-deoB-deoD)-serB-thr. Studies on polarity mutants and induction patterns indicate that the deoBand deoDgenes may constitute a single operon and that the deoCand deoAgenes may constitute a second closely linked operon.

Englesberg, E. (University of Pittsburgh, Pittsburgh, Pa.), R L. Anderson, R. Weinberg, N. Lee, P. Hoffee, G. Huttenhauer, and H. Boyer. l-Arabinose-sensitive, l-ribulose 5-phosphate 4-epimerase-deficient mutants of Escherichia coli. J. Bacteriol. 84:137–146. 1962—l-Arabinose-negative mutants of Escherichia coliB/r, ara-53 and ara-139, are deficient in the enzyme l-ribulose 5-phosphate 4-epimerase; ara-53, further analyzed, accumulates large quantities of l-ribulose 5-phosphate when incubated with l-arabinose. The mutant sites are closely linked to the left of the previously ordered l-arabinose mutant sites, and probably represent the structural gene for l-ribulose 5-phosphate 4-epimerase (gene D) in the l-arabinose operon. The inducible levels of l-arabinose isomerase and l-ribulose 5-phosphate 4-epimerase vary correspondingly as a result of mutation in the structural gene for l-ribulokinase (gene B), further substantiating the dual structural and regulatory function of this gene locus. Ara-53 and ara-139 are strongly inhibited by l-arabinose and give rise to l-arabinose-resistant mutants. The one resistant mutant analyzed still lacks the 4-epimerase but is deficient in l-ribulokinase and has increased l-arabinose isomerase activity, a characteristic of a type of mutation in the B gene. It is proposed that accumulation of l-ribulose 5-phosphate is responsible for the inhibition, and that mutation to resistance will involve mutation in the A, B, C, permease, or repressor genes, thus providing a direct method for isolating these types of l-arabinose-negative mutants. Glucose prevents and cures the l-arabinose inhibition.

Phosphodeoxyribomutase, the enzyme which catalyzes the interconversion of 2-deoxyribose-1-phosphate to 2-deoxyribose-5-phosphate, has been partially purified from Salmonella typhimurium. The enzyme had an absolute requirement for manganese ion and was stimulated by glucose-1, 6-diphosphate. Phosphodeoxyribomutase was induced by deoxyribose-5-phosphate and was coordinately regulated with the enzymes thymidine phosphorylase and deoxyribose-5-phosphate aldolase, type II. Mutants deficient in these three enzymes were isolated and mapped close to the threonine locus in S. typhimurium. The three enzymes thymidine phosphorylase, deoxyribose-5-phosphate aldolase, type II, and phosphodeoxyribomutase are controlled by a series of linked genes and appear to constitute an operon.

Salmonella typhimuriumwas found to utilize 2-deoxyribose as a sole carbon and energy source. Cells grown in the presence of deoxyribose contained increased levels of deoxyribose kinase, thymidine phosphorylase, and two forms of deoxyribose-5-phosphate aldolase (DR5P aldolase). One form of DR5P aldolase was induced by deoxyribose and coordinately regulated with deoxyribose kinase. The second form of DR5P aldolase was induced by deoxyribose-5-phosphate and coordinately regulated with thymidine phosphorylase. Mutants unable to ferment deoxyribose have been isolated and shown to be lacking either deoxyribose kinase or deoxyribose permease, but none has been found from which DR5P aldolase is missing. Thymine-requiring mutants which are able to grow on low levels of thymine have been isolated and shown, in some cases, to be lacking one or both DR5P aldolases.

The article presents an interview with Pam Hoffee, managing director at Avalon Waterways. Topics discussed include the introduction of Active Discovery cruises in 2017, the difference between passengers on Active Discovery cruises and those on Avalon's other European itineraries, and suggestions to travel agents regarding Active Discoverycruises.

In Salmonella typhimurium, the order of the deogenes with respect to the serBlocus has been determined as deoC-deoA-deoB-deoD-serB-thr.

WHEN a sensitive bacterial cell is exposed to a temperate bacteriophage it may undergo lysis, become lysogenized, or remain uninfected. The relative frequency with which these responses occur depends on the genetic structure of the phage and the conditions of the infection. The outcome may be influenced by temperature1, multiplicity of infection2, and the addition of various chemicals3,4. In a recent paper5, it was reported that glucose added to a nutrient agar medium affected a 100 per cent lysogenic response with Salmonella typhimurium strain LT2 (C+dgs)6and phage PLT22, while a glucose diauxie-resistant variant of this strain (C+dgr−1)6was found to be immune to this apparent glucose effect. These conclusions were based on observations of ‘turbid’ or ‘less turbid’ plaques as the criteria for lysogenization or lysis, respectively, of the initially infected cell. Recent attempts to duplicate these experiments were not successful, nor could any glucose effect on the frequency of lysogenization be detected using a more direct and reliable method developed by Luria and Fraser (ref. 4). (We wish to thank E. Bertani for details of the method and the indicator strain.)