Antimicrobial and Antimycobacterial Activity of Cyclostellettamine Alkaloids from Sponge Pachychalina sp.     

Jaine H. H. L. de Oliveira  Mirna H. R. Seleghim  Christoph Timm  Achim Grube  Matthias K?ck  Gislene G.F. Nascimento  Ana Claudia T. Martins  Elissa G. O. Silva  Ana Olívia de Souza  Paulo R. R. Minarini  Fabio C. S. Galetti  Célio L. Silva  Eduardo Hajdu  Roberto G. S. Berlinck 《Marine drugs》2006,4(1):1-8

Cyclostellettamines A – F (1 – 6) isolated from the sponge Pachychalina sp. and cyclostellettamines G - I, K and L (7 – 11) obtained by synthesis were evaluated in bioassays of antimicrobial activity against susceptible and antibiotic-resistant Staphylococcus aureus, Pseudomonas aeruginosa and antibiotic-susceptible Escherichia coli and Candida albicans, as well as in antimycobacterial activity against Mycobacterium tuberculosis H37Rv bioassays. The results obtained indicated that cyclostellettamines display different antimicrobial activity depending on the alkyl-chain size, suggesting that, if a mechanism-of action is implied, it is dependent on the distance between the two pyridinium moieties of cyclostellettamines.  相似文献   

Exposure of domestic swine to influenza A viruses in Ghana suggests unidirectional,reverse zoonotic transmission at the human–animal interface     

Matilda Ayim‐Akonor  Eva Mertens  Jürgen May  Timm Harder 《Zoonoses and public health》2020,67(6):697-707

Influenza A viruses (IAVs) have both zoonotic and anthroponotic potential and are of public and veterinary importance. Swine are intermediate hosts and ‘mixing vessels’ for generating reassortants, progenies of which may harbour pandemic propensity. Swine handlers are at the highest risk of becoming infected with IAVs from swine but there is little information on the ecology of IAVs at the human–animal interface in Africa. We analysed and characterized nasal and throat swabs from swine and farmers respectively, for IAVs using RT‐qPCR, from swine farms in the Ashanti region, Ghana. Sera were also analysed for IAVs antibodies and serotyped using ELISA and HI assays. IAV was detected in 1.4% (n = 17/1,200) and 2.0% (n = 2/99) of swine and farmers samples, respectively. Viral subtypes H3N2 and H1N1pdm09 were found in human samples. All virus‐positive swine samples were subtyped as H1N1pdm09 phylogenetically clustering closely with H1N1pdm09 that circulated among humans during the study period. Phenotypic markers that confer sensitivity to Oseltamivir were found. Serological prevalence of IAVs in swine and farmers by ELISA was 3.2% (n = 38/1,200) and 18.2% (n = 18/99), respectively. Human H1N1pdm09 and H3N2 antibodies were found in both swine and farmers sera. Indigenous swine influenza A viruses and/or antibodies were not detected in swine or farmers samples. Majority (98%, n = 147/150) of farmers reported of not wearing surgical mask and few (4%, n = 6) reported to wear gloves when working. Most (n = 74, 87.7%) farmers reported of working on the farm when experiencing influenza‐like illness. Poor husbandry and biosafety practices of farmers could facilitate virus transmission across the human–swine interface. Farmers should be educated on the importance of good farm practices to mitigate influenza transmission at the human–animal interface.  相似文献   

The herbicide binding niche of photosystem II-a model     

Klaus G. Tietjen  Joachim F. Kluth  Roland Andree  Michael Haug  Markus Lindig  Klaus H. Müller  Heinz J. Wroblowsky  Achim Trebst 《Pest management science》1991,31(1):65-72

The Q_B binding niche of photosystem II is also the binding site for many different herbicides. In order to understand the mode of binding of the herbicides, a 3-dimensional model of the binding niche was constructed. The model was based upon a comparison of the known structure of the Q_B binding niche in purple bacteria with sequence and mutant data of the D-1 protein of photosystem II. Plastoquinone builds up hydrogen bonds to phenylalanine 265 backbone amide nitrogen, to serine 264 hydroxyl, and to histidine 215 delta-1 nitrogen. In addition to these hydrogen bond donors and acceptors, herbicides can build up hydrogen bonds to backbone carbonyl of alamine 263 and to serine 268 hydroxyl. This is supported by binding data of inhibitors in Chlamydomonas reinhardtii chloroplasts of wild type and of five D-1 protein mutants (Ser264 Ala, Ala251 Val, Phe255Tyr, Val2191le, Leu275Phe).  相似文献   

Investigations on course and outcome of phocine distemper virus infection in harbour seals (Phoca vitulina) exposed to polychlorinated biphenyls. Virological and serological investigations.     

T C Harder  T Willhaus  W Leibold  B Liess 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(1):19-31

The influence of polychlorinated biphenyls (PCBs) on phocine distemper virus (PDV) infections in harbour seals (Phoca vitulina) was studied. Six out of ten seals had been conditioned with a defined mixture of PCB-congeners for several weeks. Following exposure to the cell culture-propagated PDV isolate 2558/Han 88 the complete clinical picture of "1988 seal plague" was provoked in all ten seals inoculated. Four out of six PCB-conditioned seals and two out of four seals not loaded with PCBs succumbed to the infection within three weeks post inoculation. With regard to the clinical course, duration of cell-associated viremia, PDV-antigen distribution in tissues of fatally infected seals and the humoral immune response to PDV no differences between PCB-loaded and unloaded seals were recognized. Evidence was obtained that the pathogenesis of experimental PDV-infection in harbour seals shares some features with those of canine distemper in terrestrial carnivores. In contrast, however, to experimental distemper infection of gnotobiotic dogs prompt development of high titres of PDV-specific IgG did not correlate with recovery from infection.  相似文献   

Defective lipolysis and altered energy metabolism in mice lacking adipose triglyceride lipase     

Haemmerle G  Lass A  Zimmermann R  Gorkiewicz G  Meyer C  Rozman J  Heldmaier G  Maier R  Theussl C  Eder S  Kratky D  Wagner EF  Klingenspor M  Hoefler G  Zechner R 《Science (New York, N.Y.)》2006,312(5774):734-737

Fat tissue is the most important energy depot in vertebrates. The release of free fatty acids (FFAs) from stored fat requires the enzymatic activity of lipases. We showed that genetic inactivation of adipose triglyceride lipase (ATGL) in mice increases adipose mass and leads to triacylglycerol deposition in multiple tissues. ATGL-deficient mice accumulated large amounts of lipid in the heart, causing cardiac dysfunction and premature death. Defective cold adaptation indicated that the enzyme provides FFAs to fuel thermogenesis. The reduced availability of ATGL-derived FFAs leads to increased glucose use, increased glucose tolerance, and increased insulin sensitivity. These results indicate that ATGL is rate limiting in the catabolism of cellular fat depots and plays an important role in energy homeostasis.  相似文献   

Lumber recovery and value of dead and sound black spruce trees grown in the North Shore region of Québec     

Julie Barrette  David Pothier  David Auty  Alexis Achim  Isabelle Duchesne  Nancy Gélinas 《Annals of Forest Science》2012,69(5):603-615

Context

To increase the wood supply to its industry, the government of Québec has allocated dead and sound wood (recently dead merchantable stems, DSW) to the wood supply chain in addition to the annual allowable cut of living trees. However, DSW is often criticized by sawmillers for its perceived poor quality and lower value.

Aims

The objective of this study was to compare the lumber visual grade yield and value from live and recently dead merchantable trees in three different states of wood decomposition.

Methods

In total, 162 black spruce trees [Picea mariana (Mill.) BSP] were felled from three different sites comprising three different states of wood decomposition and three diameter classes. The state of decomposition of each standing tree was categorized following Hunter??s classification (decay stages 1 & 2, 3 and 4) and the DSW classification developed by the Government of Québec.

Results

Large trees (> 20?cm) of the Hunter 4 class have a lower value as a result of inferior quality.

Conclusion

Considering the current economic difficulties facing the forest industry and the requirements of ecosystem-based management, we recommend leaving in the forest trees that have reached such a state of deterioration.  相似文献   

Influence of early re-spacing on Sitka spruce branch structure     

David Auty  Aaron R. Weiskittel  Alexis Achim  John R. Moore  Barry A. Gardiner 《Annals of Forest Science》2012,69(1):93-104

• Context   

The frequency, size, and insertion angle of primary branches are important determinants of wood quality and can be significantly influenced by silvicultural activities.  相似文献   

Usefulness of gene pg10 as a source of stem rust resistance in oat breeding     

Harder DE 《Phytopathology》1999,89(12):1214-1217

ABSTRACT Infection types produced by Puccinia graminis f. sp. avenae on plants of Avena sativa with the stem rust resistance gene Pg10 are characterized by moderate-sized uredinia surrounded by an area of chlorosis and a larger variable zone of dark brown necrosis. This study was undertaken to assess the effectiveness of gene Pg10 as a source of resistance to stem rust and to determine the interactions of this gene with other common Pg genes. A derived Pg10 line was tested with 58 distinct pathotypes of P. graminis f. sp. avenae and was crossed to substituted single-gene lines carrying the resistance gene Pg1, Pg2, Pg3, Pg4, Pg8, Pg9, Pg13, Pg15, Pg16, or Pga. The Pg10 line showed moderate resistance to all 58 patho-types, and there was no indication of specificity in virulence by any isolate. Gene Pg10 was inherited independently of the other Pg genes and had a complementary effect on the expression of resistance by these genes. An effective level of resistance conferred by Pg10 was demonstrated in a field nursery artificially inoculated with P. graminis f. sp. avenae. It was concluded that Pg10 is a potentially useful source of stem rust resistance in oat breeding, with its main attributes being an apparent broad base of resistance, ease of combining with other Pg genes, and complementary effects on the expression of other Pg genes.  相似文献   

Segmental aplasia of the caudal vena cava in a dog          下载免费PDF全文

Harder MA  Fowler D  Pharr JW  Tryon KA  Shmon C 《The Canadian veterinary journal. La revue veterinaire canadienne》2002,43(5):365-368

Ultrasonography, angiography, magnetic resonance imaging, and exploratory laparotomy of a 2-year-old wheaten terrier with lethargy, exercise intolerance, and ascites revealed segmental aplasia of the caudal vena cava with azygos continuation, complicated by thrombus formation. Surgeries were performed on the blind-ended vessel to remove thrombi, enhancing shunting of blood through the azygos vein.  相似文献   

IRON BACTERIA     

Harder EC 《Science (New York, N.Y.)》1915,42(1079):310-311

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