The spark discharge synthesis of amino acids from various hydrocarbons

The spark discharge synthesis of amino acids using an atmosphere of CH₄ + N₂ + H₂O + NH₃ has been investigated with variable pNH₃. The amino acids produced using higher hydrocarbons (ethane, ethylene, acetylene, propane, butane, and isobutane) instead of CH₄ were also investigated. There was considerable range in the absolute yields of amino acids, but the yields relative to glycine (or -amino-n-butyric acid) were more uniform. The relative yields of the C₃ to C₆ aliphatic -amino acids are nearly the same (with a few exceptions) with all the hydrocarbons. The glycine yields are more variable. The precursors to the C₃-C₆ aliphatic amino acids seem to be produced in the same process, which is separate from the synthesis of glycine precursors. It may be possible to use these relative yields as a signature for a spark discharge synthesis provided corrections can be made for subsequent decomposition events (e.g. in the Murchison meteorite).     

Interactions of Metarhizium anisoplae and tree-based mulches in repellence and mycoses against Coptotermes formosanus (Isoptera: Rhinotermitidae)

The use of mulch in urban landscapes has increased in the United States for the past decade. Tree-based organic mulches can supply Coptotermes formosanus Shiraki with food, moisture, and shelter. The current research contributes to mulch management technology in termite control. A choice test arena was designed to determine the repellence and mortality caused by commercial mulches treated with different concentrations of the fungus Metarhizium anisopliae (Metschnikoff) against C. formosanus. Each of six tree-based mulches (pine bark, pine straw, bald cypress, eucalyptus, water oak, and melaleuca) was coated with six conidial concentrations ranging from 1 x 10(3) to 1 x 10(8) conidia/ml. The foragers of C. formosanus were repelled significantly by the fungal-treated mulch substrates; the proportion of termites on fungal-treated mulch was usually <20% during the 28-d test. By day 28, >99% of the termites were killed in test arenas containing a chamber with mulch treated with 10(7) or 10(8) conidia/ml. M. anisopliae significantly reduced mulch consumption by 34-71%. Mulch consumption by the termites was negatively correlated with fungal concentration, and the type of mulch also affected consumption. The differences in termite foraging activities, mortality, and food consumption among mulches were usually confounded by differences in fungal concentrations of M. anisopliae. The results indicate that repellence and virulence of M. anisopliae conidia should significantly reduce the suitability of these six mulches as a habitat for C. formosanus.     

The essential fatty acid status in phenylketonuria patients under treatment

Phenylketonuric patients are on a special diet that lacks certain essential fatty acids. This study evaluates the essential fatty acid status of a group of phenylketonuric patients in the Netherlands undergoing dietary treatment. To this end, the essential fatty acid status of nine phenylketonuria patients was studied. On the basis of age and gender, two control subjects were selected for each patient. The essential fatty acid composition of duplicate food portions and the essential fatty acid status of plasma and erythrocytes were analyzed. Phenylketonuria subjects had a different essential fatty acid profile from their peers, especially concerning the n-3 fatty acids. N-6 and n-3 fatty long-chain polyenes were hardly consumed by phenylketonuria subjects, in contrast to the control subjects. Linoleic acid, on the other hand, was consumed in significantly higher amounts by phenylketonuria subjects and made up about 40% of their daily fat consumption. The essential fatty acid consumption pattern of the phenylketonuria subjects is mirrored by the essential fatty acid concentrations in blood. The essential fatty acid status of the phenylketonuric diet should be improved in order to prevent deficiency in n-3 fatty acids.     

Rheology and microstructure of solutions of the microbial polysaccharide from Pseudomonas elodea

Rheological studies of solutions and gels of the microbial polysaccharide from the organism Pseudomonas elodea have been combined with X-ray diffraction studies of fibres and pulsed electric-birefringence studies of dilute solutions, to investigate the conformation and interaction of the polymer molecules. Rheological data are suggestive of a locally rigid conformation for the biopolymer in solution. X-Ray diffraction studies suggest that the molecules adopt a three-fold helical structure. O-Acetyl substituents have been shown to inhibit the packing of these helices into crystalline domains. Studies of pulsed electric-birefringence suggest an extended, kinetically rigid structure in solution. Dissolving the polysaccharide in dimethyl sulphoxide inhibits the gelation and shear-thinning characteristics of aqueous solutions. Comparative studies of electric birefringence of solutions in water and dimethyl sulphoxide suggest that the differences in rheological properties may result from a change in molecular conformation.     

An arabinogalactoxyloglucan from the cell wall of Solanum tuberosum

Cell-wall material from potatoes was fractionated by successive extractions with water at 80°, 0.2 M (NH₄)₂C₂O₄ at 80°, 1 M and 4 M KOH, to leave a residue of α-cellulose. The compositions of the isolated carbohydrate polymers were determined by sugar and methylation analysis. From the 4M KOH-soluble fraction an arabinogalactoxyloglucan was isolated and (partially) characterized by methylation analysis of the undegraded polymer and partially degraded methylated polymer. Methylation analysis of the oligosaccharides produced on treatment of the xyloglucan with cellulase threw additional light on the structural features of the polysaccharide. The results show that the xyloglucan has a cellulosic backbone which is highly substituted at position 6 with xylopyranose residues, some of which, in turn, carry either arabinofuranose or galactopyranose residues, as a substituent on position 2. The significance of these results is discussed.     

Untersuchungen über den Einfluß der Adaptationstemperatur auf die Resistenz und Aktivität der Transaminasen von Hefezellen

Zusammenfassung Die Hitzeresistenz und Aktivität von Transaminasen aus Candida pseudotropicalis wurde nach Adaptation der Kulturen an 20 und 40°C untersucht. Mit Anpassung an die höhere Temperatur nahm die Hitzeresistenz der Asparaginsäure--Ketoglutarsäure-Transaminase (AKT) zu. Die Substrate der AKT, Asparaginsäure, Pyridoxalphosphat und besonders -Ketoglutarsäure, verliehen dem Enzym aus beiden Adaptationstemperaturen eine höhere Hitzeresistenz. Durch weitere Aminosäuren wurde dagegen keine nennenswerte Resistenzsteigerung hervorgerufen. Der Hitzedenaturierung ging eine Aktivierung voraus, die bei Anwesenheit der stabilisierenden Substrate besonders ausgeprägt war/Die Aktivität der AKT war bei der an 40°C adaptierten Hefe erheblich höher als bei der 20^o-Hefe, dagegen konnte eine Leucin-Oxalessigsäure-Transaminase nur bei der tieferen, Adaptationstemperatur beobachtet werden. Zugabe von Pyridoxalphosphat steigerte die AKT-Aktivität in zellfreien Extrakten, und zwar am stärksten bei der weniger aktiven 20^o-Hefe. Die durch die unterschiedlichen Adaptationstemperaturen bedingten Leistungsunterschiede konnten durch das Coenzym teilweise ausgeglichen werden.Der Deutschen Forschungsgemeinschaft danken wir, für die Gewährung einer Sachbeihilfe.     

Mortality from myocardial infarction in different types of hospitals.

Hospitals ranging from large urban teaching hospitals to small country hospitals were stratified into four levels of care and examined for their effectiveness of coronary care in relation to these levels. The crude hospital mortality among 2265 patients admitted for definite or possible acute myocardial infarction was 21% at level 1 (the most elaborate level), 22% at level 2, 21% at level 3, and 19% at level 4 (the least elaborate). Adjustment for age or other prognostic factors produced no significant differences across levels either for coronary care unit care or for combined coronary unit and ward care. Success in resuscitation was also similar across levels. These findings suggest that increased resources for coronary care units--whether for new services or for upgrading existing ones--may not be required.     

A stress-responsive system for mitochondrial protein degradation

We show that Ydr049 (renamed VCP/Cdc48-associated mitochondrial stress-responsive--Vms1), a member of an unstudied pan-eukaryotic protein family, translocates from the cytosol to mitochondria upon mitochondrial stress. Cells lacking Vms1 show progressive mitochondrial failure, hypersensitivity to oxidative stress, and decreased chronological life span. Both yeast and mammalian Vms1 stably interact with Cdc48/VCP/p97, a component of the ubiquitin/proteasome system with a well-defined role in endoplasmic reticulum-associated protein degradation (ERAD), wherein misfolded ER proteins are degraded in the cytosol. We show that oxidative stress triggers mitochondrial localization of Cdc48 and this is dependent on Vms1. When this system is impaired by mutation of Vms1, ubiquitin-dependent mitochondrial protein degradation, mitochondrial respiratory function, and cell viability are compromised. We demonstrate that Vms1 is a required component of an evolutionarily conserved system for mitochondrial protein degradation, which is necessary to maintain mitochondrial, cellular, and organismal viability.