A semi-natural habitat for housing small,nonhuman primates

A semi-natural habitat that was designed to house a social group of squirrel monkeys (Saimiri sciureus sciureus) at Goucher College, in Maryland is described. The design could be readily adapted for use with other small primate species.     

Competition by 4-chloronitrosobenzene for the active glycolaldehyde intermediate of transketolase

The incubation of 4-chloronitrosobenzene with yeast transketolase, Mg²⁺, and thiamime pyrophosphate in the presence of excess xylulose-5-phosphate resulted in the formation of N-(4-chlorophenyl)glycolhydroxamic acid. This enzyme-catalyzed C₂ transfer displayed a K_m of 0.92 mM and a V_max of 5.2 × 10^?2 μmol min^?1 unit enzyme^?1. Conversion was inhibited by the normal acceptor sugar, ribose-5-phosphate, with a K_i of 0.35 mM. Kinetic analysis showed inhibition was competitive in nature, reinforcing the proposed theory for similarity in catalytic formation of both the hydroxamic acid and sedoheptulose-7-phosphate. Most interesting about the conversion of this alternative substrate is that even at high concentrations of ribose-5-phosphate, a significant amount of the nitroso compound was converted to the hydroxamic acid, implying that 4-chloronitrosobenzene can successfully compete for active glycoaldehyde. Using the yeast enzyme as a model for transketolase in higher organisms, the adventitious conversion of such xenobiotics in vivo is proposed.     

Osmotic shock improves <Emphasis Type="Italic">Tnt1</Emphasis> transposition frequency in <Emphasis Type="Italic">Medicago truncatula</Emphasis> cv Jemalong during in vitro regeneration

Insertion mutant collections are powerful tools for genetic studies in plants. Although large-scale insertional mutagenesis using T-DNA is not feasible in legumes, the Tnt1 tobacco retrotransposon can be used as a very efficient mutagen in the Medicago truncatula R108 genotype. In this article, we show that Tnt1 can also be exploited to create insertional mutants via transformation and/or regeneration in the reference cultivar Jemalong. Tnt1 insertional mutagenesis in Jemalong following Agrobacterium tumefaciens-mediated transformation was found to be very efficient, with an average of greater than 15 insertions/line. In contrast, regeneration using low-copy transgenic starter lines resulted in a highly variable rate of new Tnt1 insertions. With the goal of increasing the number of additional Tnt1 insertions during regeneration of starter lines, we have compared the insertion frequencies for a number of different regeneration protocols. In addition, we have been able to show that sucrose-mediated osmotic shock preceding regeneration significantly increases the transposition frequency. Under optimal conditions, 95% of the regenerated Jemalong plants possess new insertions.     

Adenovirus adsorption and sterol redistribution in KB cell plasma membrane

Filipin was used as a chemical probe for localization of sterols in freeze-fractured plasma membrane of KB cells. After adenovirus particle adsorption, marked changes occurred in the number and planar distribution of sterols and of intramembranous particles (IMPs). Filipin-sterol complexes became more abundant and both sterols and IMPs aggregated in a network pattern. It was suggested that redistribution of sterols and rearrangement of IMPs were interconnected phenomena, which represented an early cellular response to adenovirus attachment.     

Genetic analysis of viable and lethalfused mutants ofDrosophila melanogaster

Summary Fused is a segmentation gene belonging to the segment-polarity class. Mutations at thefused locus are known to display pleiotropic effects, causing zygotically determined anomalies of ovaries and of some adult cuticular structures, and maternally determined embryonic segmentation defects. In order to determine the amorphic phenotype offused and to study the genetical basis of its pleiotropy, newfused alleles (18 viable and 11 lethal) were isolated. The phenotype of these mutants and of others already known are described, taking into account zygotic and maternal effects. The main results provided by this analysis are as follows. Firstly, allfused alleles show the whole complex fused phenotype, and a good correlation is observed between the strength of the wing and segmentation defects, suggesting that a single function is involved in both processes. Secondly, all embryonic and larval lethals carry deficiencies which allow us to localizefused between the 17C4 and 17D2 bands of the X-chromosome. Thirdly, the 24 viable and 2 pupal lethals examined behave as point mutants, as shown cytologically or by Southern blot analysis. However, only one of them, the pupal lethalfu ^mH63 was proven to carry a nullfused allele, since it displays in germ-line clones a strong maternal phenotype and a very low zygotic rescue, similar to those of the small deficiencyDf(1)fu ^z4. The phenotype of the amorphic mutant indicates that zygotic ezpression offused is required for normal metamorphosis, while maternal expression is necessary for a normal segmentation pattern, since a complete loss offused expression during oogenesis cannot be compensated zygotically.     

Antimicrobial effects of plant extracts on Streptococcus mutans, Candida albicans, Trichophyton rubrum and other micro-organisms

Extracts of 54 plant species were tested for ability to inhibit bacteria and fungi, especially Candida albicans, Trichophyton rubrum and Streptococcus mutans. The latter three species cause common dermal, mucosal, or oral infections in humans that are difficult to control effectively. Fifteen plant extracts produced detectable antimicrobial activity. The most active included Celastrus scandens root bark, Juglans nigra fruit husks, Kalmia latifolia leaves, Pelargonium xhortorum leaves, and Rhus glabra root bark. Five plant species inhibited Strep. mutans , four inhibited T. rubrum , and two inhibited C. albicans. Lindera benzoin , a common temperate zone shrub, showed evidence of selective toxicity. Extract of L. benzoin bark strongly inhibited C. albicans and T. rubrum , but did not affect any of the other microorganisms tested.