Purification and characterization of hepatic triacylglycerol lipase isolated from rainbow trout,Oncorhynchus mykiss     

Jamie S. Harmon  Kim G. Michelsen  Dr. Mark A. Sheridan 《Fish physiology and biochemistry》1991,9(4):361-368

Trialcylglycerol (TG) lipase was isolated and partially purified from rainbow trout liver. Triacylglycerol lipase activity was assayed by measuring¹⁴C-oleic acid release from¹⁴C-triolein.¹⁴C-oleic acid release was linear for up to two hours. Optimal activity occurred at pH 7.0 and 15°C. Most of the lipase activity was recovered in the cytosolic fraction. A 27,000-fold purification was achieved after Sepharose (Bio-gel A 0.5 M, 200–400 mesh) chromatography of a resuspended 20% ammonium sulfate fraction. The molecular weight of the trout hepatic lipase as determined by size-exclusion chromatography and by SDS-polyacrylamide gel electrophoresis was 40–43 kD. Lipase-mediated hydrolysis of TG resulted in the production of diacylglycerols, monoacylglycerols, and fatty acids. Kinetic analysis indicated that V_max=0.016 nmol/h/mg protein and that K_m=0.28 mM triolein. Lipolytic activity was enhanced in the presence of cAMP/ATP-Mg²⁺. These results suggest that the liver of trout possesses a neutral TG lipase that is responsible for mobilizing stored TG and is catalytically activated by phosphorylation.A part of this work was presented at the Annual Meeting of the American Society of Zoologists, December 26–30, 1990, San Antonio, TX.  相似文献   

Carcinogen in rock fern (Chielanthes sieberi) from New Zealand and Australia     

BL SMITH  PP EMBLING  DR LAUREN  MP AGNEW  AD ROSS  PL GREENTREE 《Australian veterinary journal》1989,66(7):230-231

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The occurrence of and organisms concerned with bovine mycotic abortion in some counties of Ireland     

J. J. Sheridan  D. S. C. White  Q. D. McGarvie 《Veterinary research communications》1985,9(1):221-226

Bovine mycotic abortion in some counties of the Irish provinces of Leinster and Ulster was estimated at 1–2% of all abortions for which a causal agent was identified in the years from 1969 to 1978. The organism most commonly isolated from diseased specimens wasAspergillus fumigatus, followed byAbsidia corymbifera. There was no relationship between the incidence of the disease in any year and the rainfall or number of raindays during the previous summer. The data obtained are discussed in relation to the occurrence of the disease in the United Kingdom.  相似文献   

Anemia amelioration by lactose infusion during trypanosomosis could be associated with erythrocytes membrane de-galactosylation     

E.O. Balogun  J.B. Balogun  S. Yusuf  H.M. Inuwa  I.S. Ndams  P. Sheridan  D.K. Inaoka  T. Shiba  S. Harada  K. Kita  K.A.N. Esievo  A.J. Nok 《Veterinary parasitology》2014,199(3-4):259-263

African trypanosomosis is a potentially fatal disease that is caused by extracellular parasitic protists known as African trypanosomes. These parasites inhabit the blood stream of their mammalian hosts and produce a number of pathological features, amongst which is anemia. Etiology of the anemia has been partly attributed to an autoimmunity-like mediated erythrophagocytosis of de-sialylated red blood cells (dsRBCs) by macrophages. Lactose infusion to infected animals has proven effective at delaying progression of the anemia. However, the mechanism of this anemia prevention is yet to be well characterized. Here, the hypothesis of a likely induced further modification of the dsRBCs was investigated. RBC membrane galactose (RBC m-GAL) and packed cell volume (PCV) were measured during the course of experimental trypanosomosis in mice infected with Trypanosoma congolense (stb 212). Intriguingly, while the membrane galactose on the RBCs of infected and lactose-treated mice (group D) decreased as a function of parasitemia, that of the lactose-untreated infected group (group C) remained relatively constant, as was recorded for the uninfected lactose-treated control (group B) animals. At the peak of infection, the respective cumulative percent decrease in PCV and membrane galactose were 30 and 185 for group D, and 84 and 13 for group C. From this observed inverse relationship between RBCs membrane galactose and PCV, it is logical to rationalize that the delay of anemia progression during trypanosomosis produced by lactose might have resulted from an induction of galactose depletion from dsRBCs, thereby preventing their recognition by the macrophages.  相似文献   

Genetic diversity within commercial populations of watercress (Rorippa nasturtium-aquaticum), and between allied Brassicaceae inferred from RAPD-PCR     

G.E.C. Sheridan  J.R. Claxton  J.M. Clarkson  D. Blakesley 《Euphytica》2001,122(2):319-325

Commercial productivity of watercress (Rorippa nasturtium-aquaticum) can be adversely affected by the pathogenic crook-root fungus, Spongospora subterranea f.sp. nasturti, and watercress viruses. As there are no effective control measures for these diseases, attempts have been made to breed varieties resistant to the crook-root pathogen. This work has been hindered by a lack of knowledge of the genetic base of commercial watercress, and the genetic distance between watercress and allied Brassicaceae which have been identified as candidates for hybridisation programmes. We measured the diversity within these two groups using the RAPD-PCR fingerprinting technique and analysed the data by both distance methods and principal co-ordinate analysis. Little genetic diversity was found within commercial watercress populations. However, watercress formed a unique cluster genetically distinct from other Rorippa species, but equidistant to Cardamine species. It was placed closer to Barbarea verna. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Advances in cell biology: gap junctions     

Sheridan JD 《Science (New York, N.Y.)》1989,243(4891):674-675

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Careers in science. More women in science     

Handelsman J  Cantor N  Carnes M  Denton D  Fine E  Grosz B  Hinshaw V  Marrett C  Rosser S  Shalala D  Sheridan J 《Science (New York, N.Y.)》2005,309(5738):1190-1191

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Identity and search in social networks     

Watts DJ  Dodds PS  Newman ME 《Science (New York, N.Y.)》2002,296(5571):1302-1305

Social networks have the surprising property of being "searchable": Ordinary people are capable of directing messages through their network of acquaintances to reach a specific but distant target person in only a few steps. We present a model that offers an explanation of social network searchability in terms of recognizable personal identities: sets of characteristics measured along a number of social dimensions. Our model defines a class of searchable networks and a method for searching them that may be applicable to many network search problems, including the location of data files in peer-to-peer networks, pages on the World Wide Web, and information in distributed databases.  相似文献   

Further studies with a sex-linked lethal gene in the fowl     

A K Sheridan 《British poultry science》1979,20(6):571-573

1. The ladykiller (lk) gene has been located on the sex chromosome of the fowl. It is 4.2 map units distant from the feathering rate locus (k) and 11.2 map units distant from the dwarf (dw) locus. 2. Most of the embryonic mortalities associated with this gene occurred between 3 and 4 d of incubation.  相似文献   

A CULTURAL METHOD OF DETERMINING THE VIABILITY OF SEPTORIA SPORES FROM CELERY SEED     

J. E. Sheridan 《Plant pathology》1963,12(4):172-173

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