Manganese (Mn2+)-dependent storage stabilization of Rhodotorula glutinis phenylalanine ammonia-lyase activity

Phenylalanine ammonia-lyase (PAL; E C 4.3.1.5) reverse reaction has been exploited for the commercial production of optically pure l-phenylalanine from trans-cinnamic acid. Optimal conditions for the growth and PAL activity of Rhodotorula glutinis cells and an improved method for the synthesis of l-phenylalanine have been reported. A major problem encountered during these studies was rapid loss of PAL activity during storage of the yeast cells, which were therefore unsuitable for long-term and repeated use. Enhancement of enzyme stability in the presence of various additives including polyhydric compounds and metal ions is described. Whole cells retained nearly 85% of the original enzyme activity for at least 12 weeks when a low concentration of Mn2+ (0.01%) was included in the storage buffer medium (50 mM Tris-HCl, pH 8.8). In contrast, <3.0% activity was present in the control within 4 weeks. Mn2+-dependent stabilization of PAL was also observed with an isolated enzyme preparation (73% retention in activity for 12 weeks) obtained by ultrasonication of R. glutinis whole cells. The data suggest that Mn2+ ions may be responsible for the specific stabilization of a more active conformation of the enzyme. In addition, enzyme stability as a function of temperature was studied, and the optimal temperature for maximal activity retention was 0-2 degrees C. The effects of various additives on the induction of PAL have also been examined. These results could have direct implications in studies on activity, inhibition, and reaction mechanism of this biotechnologically important enzyme.     

Oocyte-somatic cell-endocrine interactions in pigs

Oocyte-somatic cell communication is bi-directional and essential for both oocyte and follicular granulosa and theca cell function and development. We have shown that the oocyte secretes factors that stimulate porcine granulosa cell proliferation in serum-free culture, and suppress progesterone production, thereby preventing premature luteinisation. Possible candidates for mediating some of these effects are the bone morphogenetic proteins (BMPs) that belong to the transforming growth factor beta family. They are emerging as a family of proteins critical for fertility and ovulation rate in several mammals, and they are expressed in various cell types in the ovary. We have evidence for a functional BMP system in the porcine ovary and BMP receptors are present in the egg nests in the fetal ovary and in the granulosa cells, oocytes and occasional theca cells throughout subsequent development. In addition to paracrine interactions in the ovary, the porcine oocyte and its developmental potential can also be influenced by nutritional manipulation in vivo. We have demonstrated that feeding a high plane of nutrition to gilts for 19 days prior to ovulation increased oocyte quality compared to control animals fed a maintenance diet, as determined by oocyte maturation in vitro. This was associated with a number of changes in circulating reproductive and metabolic hormones and also in the follicular fluid in which the oocyte is nurtured. Further studies showed a similar increase in prenatal survival on Day 30 of gestation, demonstrating a direct link between oocyte quality/maturation and embryo survival. Collectively, these studies emphasise the importance of the interactions that occur between the oocyte and somatic cells and also with endocrine hormones for ovarian development, and ultimately for the production of oocytes with optimal developmental potential.     

Efficacy of monensin and tylosin in finishing diets based on steam-flaked corn with and without corn wet distillers grains with solubles

Three hundred seventy-one crossbred-yearling heifers (299 +/- 9 kg initial BW) were obtained from a common source and used in a randomized complete-block designed finishing study. A 2 x 3 factorial arrangement of treatments was used with one factor being diet: based on steam-flaked corn finishing diet (SFC) or SFC plus 25% (dry basis) corn wet distillers grains with solubles (WDGS). The second factor was feed additives: no added antibiotics (NONE), 300 mg of monensin daily (MONENSIN), or 300 mg of monensin + 90 mg of tylosin daily (MON+TYL). Main effect of diet resulted in no difference in DMI (P = 0.34). Heifers fed SFC gained 9% faster (P = 0.01) and were 7% more efficient (P = 0.01) than heifers fed WDGS. In addition, heifers fed SFC had 3% heavier (P = 0.01) HCW; 1% greater (P = 0.01) dress yield; and had 3% larger (P = 0.05) LM area. Marbling score and carcasses that graded USDA Choice or better were both greater (P /= 0.12) among feed additive treatments. Kidney, pelvic, and heart fat and s.c. fat thickness at the 12th rib were also not different (P >/= 0.55) for main effects of diet and feed additive. There was a tendency (P = 0.09) for a diet x feed additive interaction for the most severe (A+) liver abscesses. Heifers fed NONE yielded the greatest percentage (16%) of A+ livers in the SFC treatment, whereas heifers fed MON+TYL yielded the greatest percentage (10%) in the WDGS treatment. Including wet distillers grains with solubles in diets based on steam-flaked corn decreased finishing heifer performance, HCW, and marbling. Tylosin addition tended to decrease severity of liver abscesses in diets containing SFC, but not in diets containing WDGS. These data indicate that monensin and tylosin may not be as effective when used in steam-flaked corn diets with 25% WDGS.     

Potent Cytotoxic Peptides from the Australian Marine Sponge Pipestela candelabra

Two consecutive prefractionated fractions of the Australian marine sponge extract, Pipestela candelabra, were identified to be selectively active on the human prostate cancer cells (PC3) compared to the human neonatal foreskin fibroblast non-cancer cells (NFF). Twelve secondary metabolites were isolated in which four compounds are new small peptides. Their structures were characterized by spectroscopic and chemical analysis. These compounds inhibited selectively the growth of prostate cancer cells with IC₅₀ values in the picomolar to sub-micromolar range. Structure-activity relationship of these compounds is discussed.     

Use of 2-aminobutane as a fumigant for control of gangrene,skin spot and silver scurf diseases of potato tubers

Summary Fumigation of tubers with 2-aminobutane (sec-butylamine) gas at a dosage of 200 mg/kg in simply made fumigation chambers gave very good control of the diseases gangrene (caused byPhoma exigua var.foveata) and skin spot (Oospora pustulans) if treatment was done within 14 days of harvesting. Some control of silver scurf disease (Helminthosporium solani) was also obtained, but results were always poorer than with gangrene or skin spot. Fumigation did not control tuber blight (Phytophthora infestans), dry rot (Fusarium solani var.caeruleum) and did not kill the sclerotia ofRhizoctonia solani. Since chemical analysis of treated peeled and boiled tubers, and crisps, granules and flakes made from treated tubers showed that they contained substantial residues of 2-aminobutane, the treatment can only be used on seed tubers. There were no significant residues in crops grown from treated tubers.

---

Zusammenfassung Jedes Jahr k?nnen Pilzkrankheiten an Kartoffelknollen betr?chtliche Verluste verursachen. In Schottland ist die Phoma-Knollenf?ule, verursacht durch den PilzPhoma exigua var.foveata, die bedeutendste Krankheit, doch ist die Tüpfelfleckenkrankheit, hervorgerufen durchOospora pustulans, ebenfalls wichtig, vor allem weil sie die Keime bef?llt. Silberschorf, verursacht durchHelminthosporium solani, ist sehr verbreitet, aber obwohl er die Keime nicht bef?llt, werden durch ihn die Knollen missgebildet, und er verursacht Welke infolge des Wasserverlustes durch die besch?digte Schale. Begasung von Knollen mit 2-Aminobutan (sek-Butylamin)-Dampf in einer Dosierung von 200 mg/kg innerhalb 14 Tage nach der Ernte wurde als ein sehr gutes Mittel zur Bek?mpfung von Phoma-Knollenf?ule und Tüpfelfleckigkeit (Tabelle 5) befunden. In zwei Versuchen ergab die Begasung eine bessere Bek?mpfung von Phoma-Knollenf?ule als das Eintauchen in eine L?sung von Quecksilbermethoxy?thylchlorid, das 100 mg/kg Quecksilber enth?lt (Tabelle 6). Eine gewisse Bek?mpfung der Silberschorfkrankheit wurde mit 2-Aminobutan erzielt (Tabelle 7), aber die Ergebnisse waren immer schlechter als bei Phoma-Knollenf?ule und Tüpfelfleckigkeit. Phytophthora-Knollenf?ule (Phytophthora infestans) und Fusarium-Trockenf?ule (Fusarium solani var.caeruleum) wurden durch die Begasung nicht bek?mpft, und auch auf die Sklerotien vonRhizoctonia solani hatte, die Begasung keinen Einfluss. Die Beurteilung der F?ulen wurde an zwei Terminen vorgenommen, einmal im Februar und dann wieder im April, w?hrend die Schalenkrankheiten, Tüpfelfleckigkeit und Phoma-Knollenf?ule im April an gewaschenen Mustern von 50 oder 100 Knollen beurteilt wurden. Der Bau der Gaskammern (dargestellt in Abb. 1 und 2) wird kurz beschrieben und der Vorgang der Begasung diskutiert. Die Kammern sind für Gas-Innenkreislauf eingerichtet, das System ist verbunden mit einem Gebl?se und einem Verdampfer. Da das 2-Aminobutan-Luftgemisch durch einen losen Kartoffelhaufen dringt, wird die Chemikalie von den unteren Knollenschichten aufgenommen; aber da der Innenkreislauf anh?lt, findet eine Abgabe und Wiederaufnahme statt, so dass der Wirkstoff, wie sich bei Rückstandsanalysen gezeigt hat, m?glicherweise gleichm?ssig im Haufen verteilt wird. Es wurde festgestellt, dass bei einer Dosis von 200 mg/kg in 30–40 Minuten und bei Luftumw?lzung w?hrend weiteren zwei Stunden die Rückst?nde in Knollenmustern von unten und oben im Haufen ?hnlich waren (Tabelle 1). Rückst?nde von 2-Aminobutan waren in signifikantem Ausmass vorhanden in gesch?lten (Tabelle 2) und gesottenen Kartoffeln sowie in Chips (Tabelle 3), ferner in Flocken und Granulaten, die aus begasten Kartoffeln hergestellt wurden, so dass das Verfahren nur bei Pflanzkartoffeln angewendet werden kann. Analysen des Nachbaus von behandelten Knollen zeigte, dass sie keine signifikanten Rückst?nde enthalten (Tabelle 4). 2-Aminobutan wird leicht verdampft (Siedepunkt 63°C) und ist schwach giftig; die Giftigkeit beruht in erster Linie auf seiner Alkalinit?t. Gewisse Vorsichtsmassnahmen müssen getroffen werden, wenn diese Substanz zur Begasung von Kartoffeln verwendet wird; sie sind in einer formellen Gebrauchsanweisung beschrieben, die von den Autoren bezogen werden kann.

---

Résumé Les maladies fongiques des tubercules de pomme de terre peuvent occasionner des pertes annuelles considérables. En Ecosse, la gangrène, causée par le champignonPhoma exigua var.foveata, est la maladie la plus grave mais, l'oosporiose, causée parOospora pustulans, est également importante, spécialement quand elle attaque les germes. La gale argentée, causée parHelminthosporium solani, est très commune, mais bien que n'attaquant pas les germes, elle détériore l'aspect des tubercules et provoque leur ramolissement par suite de la perte d'eau au travers de la peau endommagée. On a trouvé que la fumigation des tubercules avec la vapeur de 2-aminobutane (sec-butylamine), à la dose de 200 mg/kg dans les 14 jours qui suivent l'arrachage avait une très bonne efficacité dans la lutte contre la gangrène et l'oosporiose (tableau 5); de plus, dans deux essais, le résultat du traitement contre la gangrène a été supérieur au trempage dans une solution du chlorure de méthoxyethylmercurique à 100 mg/kg de mercure (tableau 6). Le 2-aminobutane a donné certains résultats dans le traitement de la gale argentée (tableau 7), mais ceux ci sont toujours inférieurs à ceux obtenus contre la gangrène et l'oosporiose. La fumigation n'a aucun effet contre le mildiou du tubercule (Phytophthora infestans) et la pourriture sèche (Fusarium solani var.caeruleum), pas plus que contre les sclérotes duRhizoctonia solani. La détermination des pourritures a été faite deux fois, une première fois en février et une seconde en avril, tandis que les déterminations des maladies de la peau, oosporiose et gangrène, ont été effectuées en avril sur des échantillons lavés de 50 ou 100 tubercules. Les auteurs décrivent brièvement la construction des chambres de fumigation (voir fig. 1 et 2) et expliquent le mécanisme de fumigation. Les chambres sont équipées pour la circulation forcée du gaz, grace à un ventilateur et un vaporisateur. Au moment où le mélange air — 2-aminobutane traverse le tas de pommes de terre, la substance chimique est absorbée par les couches inférieures de tubercules, mais grace à la circulation forcée, il se produit des phénomènes de ‘désaborption’ et de ‘réabsorption’ de telle sorte que, finalement, la substance chimique se répartit d'une mainière égale dans la masse de tubercules, comme l'indique l'analyse des résidus. Il a été démontré que si on applique la dose de 200 mg/kg pendant 30–40 minutes et qu'on réalise la circulation forcée pendant un minimum de 2 heures, les résidus dans les échantillons de tubercules sont identiques de la base au sommet du tas (tableau 1). Les résidus de 2-aminobutane sont présents en quantités significatives dans les tubercules pelés (tableau 2), bouillis et transformés en chips (tableau 3), de même dans les flocons et granulés fabriqués à partir de pommes de terre traitées, de sorte que le traitement ne peut s'appliquer qu'aux plants. L'analyse des récoltes issues de plants traités ne révèle aucune quantité significative de résidu (tableau 4). Le 2-aminobutane se vaporise aisément (63°C), est modérément toxique, la toxicité étant due en premier lieu à l'alcalinité. Il y a lieu de prendre certaines précautions dans l'emploi de cette substance dans la fumigation des pommes de terre, qui sont décrites dans le code d'emploi officiel que les auteurs peuvent fournir.

     

Effect of fumigation of potato seed tubers with 2-aminobutane on plant growth and yield

From 1968 to 1973, 13 field experiments were carried out to discover any effects of fumigation of seed tubers with 2-aminobutane (used for tuber disease control) on subsequent plant growth and yield. Nine experiments were done with tubers treated within 1 month of harvest, the remaining 4 with tubers stored for several months before treatment. In general, fumigation did not have any substantial effect on the growth pattern or the yield of the crop obtained from treated seed, although in most cases it was probable that there were small increases in the number of sprouting eyes, percentage emergence, stem number and in weight and number of seed tubers at harvest. However, these effects rarely reached levels which gave a statistically significant increase over crops grown from untreated material.     

Willingness of a Convenience Sample of Horse Owners to Use Stem Cell Therapy for the Treatment of Equine Tendon Injury and Factors that Influence This Decision

Stem cell therapies offer huge potential for the treatment of tendon injury in horses. However, the factors influencing clients' willingness to use these therapies have not yet been investigated. This study examines the willingness of a population of horse owners to choose stem cell therapy for the treatment of equine tendon injuries and the factors that may influence this choice including treatment cost and efficacy, veterinarian advice, client knowledge, and success stories. A short, anonymous questionnaire was delivered to a convenience sample of equine owners. Questions related to (1) respondent background; (2) prior experience with tendon injuries and their treatment; (3) willingness to use equine stem cell therapy; and (4) the importance of factors that may affect their decision to use the therapy. Responses were summarized using graphical methods and compared using Fisher exact test where appropriate. Fifty-four percent of our cohort (n = 113) reported they would be willing to use equine stem cell therapy, 6% were not willing, and 40% were unsure. When asked to rank factors that would influence their decision, scientific proof that the therapy works was ranked highest followed by veterinarian advice. This result may have been influenced by the high proportion of tertiary-educated respondents recruited in this study. This is the first reported study to investigate the willingness of a population of horse owners to use stem cell therapy for their horses. Results suggest that the majority of these equine owners may consider using stem cell therapies for their horses given a larger positive evidence base was provided for the therapy.     

Stormwater runoff from highways

Water, Air, & Soil Pollution - During four rain events, stormwater runoff samples from Interstate Highway 95 in Rhode Island were collected and analyzed for petroleum hydrocarbons, 14...