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Biochemical and histochemical studies have been made on non-specific acid and alkaline phosphomonoesterases of S. dentatus. The two forms of acid phosphomonoesterases have been found active at pH 4.0 and 6.0. The pH optima for the two forms of aklaline phosphomonoesterases lie at 8.0 and 10.0. Studies on the distribution of acid and alkaline phosphomonoesterases in various tissues have revealed an abundance of acid phosphomonoesterase in various parts of the alimentary canal and various organs of the reproductive system. The excretory ducts show alkaline phosphomonoesterase activity only.  相似文献   

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Nine somatic antigens derived from the excretory gland cells of adult Stephanurus dentatus were evaluated as vaccines for stephanuriasis of swine. Antigens were mixed v/v with Freund's complete adjuvant and administered intramuscularly or subcutaneously. Efficacy was evaluated by counting and comparing lesions and worms in the lymph nodes, livers, and kidney regions of principals and controls necropsied after oral challenge with infective S. dentatus larvae or after exposure to pastures naturally contaminated with such larvae. Against oral challenge, 6 vaccines produced statistically significant reductions in worm burdens of principals; 5 were significant at the 1% level and 1 at the 5% level. Two of these vaccines also reduced liver lesions significantly (P less than 0.05). Results of the natural challenge were inconclusive; small worm burdens were found in both principals and controls. None of the vaccines completely prevented migration to the liver or subsequent development and migration of a few worms to the kidney region. However, since worm burdens were reduced by as much as 92%, the vaccines could be useful in combating the disease, especially if combined with other control measures.  相似文献   

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Sixty buffalo semen samples (motility greater than 60%) were frozen in 3 extenders, viz., Tris yolk glycerol (TY-G), Citric acid whey glycerol (CAW-G) and Egg yolk glucose sodium bicarbonate glycerol (EYGSB-G) for studying the release of GOT and GPT enzymes in the extracellular fluid during pre-freezing (after first extension) and post-freezing (15 minutes and 30 days after freezing). Release of GOT and GPT enzymes was less in TY-G than CAW-G and EYGSB-G extenders. Significant differences (P<0.01) in GOT and GPT release were observed between extenders and bulls at various stages of freezing of semen.  相似文献   

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A morphological-anatomical study of Australian populations of Metamastophora flabellata (Sonder) Setchell, the type species of Metamastophora (Corallinaceae, Rhodophyta), has revealed that the primarily erect or ascending non-geniculate thallus possesses a dorsi-ventral organization of tissues. All conceptacles are uniporate and arise dorsally. Two distinct vegetative meristems occur: an apical primary meristem from which hypothallial cells are produced basipetally and a sub-epithallial secondary meristem which generates perithallial cells basipetally and secondary epithallial cells acropetally. Primary epithallial cells arise from divisions of subapical hypothallial cells. In younger parts, tissues are produced only dorsal to the hypothallium; in veins and stipes, tissue production occurs both dorsal and ventral to the hypothallium. Mature tetrasporic conceptacles contain peripheral tetrasporangia with zonately divided contents and a central sterile columella. Gametic conceptacles produce fertile tissue across the entire conceptacle chamber floor. After fertilization, the zygotic nucleus or a derivative is transferred (presumably) to an auxiliary cell through cells of the carpogonial branch; no tubular transfer siphon develops. Mature fusion cells are composed of the amalgamated supporting cells of carpogonial branches and are initiated from a single supporting cell which functions as an auxiliary cell. Unbranched 3–4 celled gonimoblast filaments arise from the fusion cell, do not become connected to other cells, and produce terminal carposporangia. Results from this study have led to a redefinition of hypothallium and perithallium in relation to meristems rather than substrate. In addition, carposporophyte ontogeny in the Corallinaceae is considered in terms of the presumed mode of transfer of the zygotic nucleus to the fusion cell, the extent of fusion cell development, and gonimoblast filament production in relation to auxiliary cells and fusion cells.  相似文献   

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The growth and morphogenesis of embryos of Aulocara elliotti (Thomas) at constant temperature are described in terms of 27 discrete morphological stages with four stages designating blastokinesis. The developmental variability of two series of embryos reared from a single wild population in two different years is compared. A bibliography to studies on other embryos of the Acrididae is included.  相似文献   

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A new assay for the determination of 5-oxoprolinase activity is described. The enzyme 5-oxoprolinase was purified from rat kidney 285-fold to apparent homogeneity, as judged by analytical disc electrophoresis and discontinous polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate. The specific activity of the preparation was 122 mU/mg of protein. A complete initial rate kinetic analysis of the forward reaction catalyzed by 5-oxoprolinase was carried out using 5-oxo-L-proline and MgATP2theta as substrates. The computer-fitted double reciprocal plots showed intersecting patterns indicating a sequential mechanism. The data were fitted by weighted linear regression analysis using the complete equation for bisubstrate reactions. The limiting Michaelis constants for 5-oxoproline and MgATP2theta were calculated to be 31.6 +/- 2.3 muM and 172.7 +/- 11.5muM, respectively. The maximum forward rate is 1.2 +/- 0.02 mumol X min-1; the turnover number 7.0 min-1.  相似文献   

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Gastric microsomes do not contain any significant Ca2+-stimulated ATPase activity. Trypsinization of pig gastric microsomes in presence of ATP results in significant (2-3 fold) increase in the basal (with Mg2+ as the only cation) ATPase activity, with virtual elimination of the K+-stimulated component. Such treatment causes unmasking of latent Mg2+-dependent Ca2+-stimulation ATPase. Other divalent cations such as Sr2+, Ba2+, Zn2+, and Mn2+ were found ineffective as a substitute for Ca2+. Moreover, those divalent cations acted as inhibitors of the Ca2+-stimulated ATPase activity. The pH optimum of the enzyme is around 6.8. The enzyme has a Km of 70 microM for ATP and the Ka values for Mg2+ and Ca2+ are about 4 x 10(-4) and 10(-7) M, respectively. Studies with inhibitors suggest the involvement of sulfhydryl and primary amino groups in the operation of the enzyme. Possible roles of the enzyme in gastric H+ transport have been discussed.  相似文献   

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A phosphatidylinositol phosphodiesterase from the culture broth of Bacillus cereus, was purified to a homogeneous state as indicated by polyacrylamide gel electrophoresis, by ammonium sulfate precipitation and chromatography with DEAE-cellulose and CM-Sephadex. The enzyme (molecular weight: 29000 +/- 1000) was maximally active at pH 7.2-7.5, AND NOT INFLUENCED BY EDTA, ophenanthroline, monoiodoacetate, p-chloromercuribenzoate or reduced glutathione. The enzyme specifically hydrolyzed phosphatidylinositol, but did not act on phosphatidylcholine, phosphatidylethanolamine and sphingomyelin, under the conditions examined. The products from phosphatidylinositol of enzyme reaction were diacylglycerols and a mixture of myoinositol 1- and 1, 2-cyclic phosphates, suggesting that the enzyme was a phosphatidylinositol-specific phospholipase C. The enzyme released alkaline phosphatase quantitatively from rat kidney slices. A kinetic analysis was made on the release of alkaline phosphatase. The results suggest that phosphatidylinositol-specific phospholipase C can specifically act on plasma membrane of rat kidney slices.  相似文献   

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