Effect of nephrotomy on renal function and morphology in normal cats     

King MD  Waldron DR  Barber DL  Larson MM  Saunders GK  Troy GC  Zimmerman-Pope N  Ward DL 《Veterinary surgery : VS》2006,35(8):749-758

OBJECTIVE: To assess effects over 12 weeks of bisection nephrotomy on renal function, size, and morphology in cats. STUDY DESIGN: Controlled, randomized, blinded experiment. SAMPLE POPULATION: Ten adult female cats. METHODS: Glomerular filtration rate (GFR), determined by quantitative renal scintigraphy using (99m)Technetium-diethylenetriamine-pentaacetic acid, urinalysis, urine culture, and ultrasonographic measurement of renal size were performed preoperatively. Left or right nephrotomy (5 cats/group) was performed. Total and individual kidney GFRs were determined at 2, 28, and 84 days, ultrasonographic measurements at 28 and 86 days, and ultrasound-guided biopsy at 86 days. RESULTS: No significant differences in mean GFR and kidney size of operated versus unoperated kidneys were observed. Individual GFR and renal size of all except 1 cat remained within normal limits. Two cats had evidence of transient ureteral obstruction in the immediate postoperative period. No significant, generalized histologic abnormalities were observed. CONCLUSIONS: Bisection nephrotomy in normal cats does not adversely affect renal function or morphology during the initial 12 weeks. CLINICAL RELEVANCE: Bisection nephrotomy can be safely performed in normal feline kidneys without causing a significant deleterious effect on renal function. Studies in cats with pre-existing renal insufficiency are needed to ensure adverse effects would not occur in clinical cases where this surgical procedure is warranted.  相似文献   

Sorption-desorption of imidacloprid and its metabolites in soil and vadose zone materials     

Papiernik SK  Koskinen WC  Cox L  Rice PJ  Clay SA  Werdin-Pfisterer NR  Norberg KA 《Journal of agricultural and food chemistry》2006,54(21):8163-8170

Sorption-desorption is one of the most important processes affecting the leaching of pesticides through soil because it controls the amount of pesticide available for transport. Subsurface soil properties can significantly affect pesticide transport and the potential for groundwater contamination. This research characterized the sorption-desorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) and three of its metabolites, 1-[(6-chloro-3-pyridinyl)methyl]-2-imidazolidinone (imidacloprid-urea), 1-[(6-chloro-3-pyridinyl)methyl]-4,5-dihydro-1H-imidazol-2-amine (imidacloprid-guanidine), and 1-[(6-chloro-3-pyridinyl)methyl]-1H-imidazol-2-amine (imidacloprid-guanidine-olefin), as a function of changing soil properties with depth in two profiles extending from the surface to a depth of 1.8 or 8 m. Sorption of each compound was highly variable and hysteretic in all cases. Normalizing the sorption coefficients (K(f)) to the organic carbon or the clay content of the soil did not reduce the variability in sorption coefficients for any compound. These results illustrate the importance of evaluation of the sorption data used to predict potential mobility. Understanding the variability of soil properties and processes as a function of depth is necessary for accurate prediction of pesticide dissipation.  相似文献   

Influence of Tithonia diversifolia and triple superphosphate on dissolution and effectiveness of phosphate rock in acidic soil     

Isaac Savini  Paul C. Smithson  Nancy K. Karanja  Hideo Yamasaki 《植物养料与土壤学杂志》2006,169(5):593-604

An incubation and a pot experiment were conducted to evaluate the dissolution and agronomic effectiveness of a less reactive phosphate rock, Busumbu soft ore (BPR), in an Oxisol in Kenya. Resin (anion and anion + cation)‐extractable P and sequentially extracted P with 0.5 M NaHCO₃, 0.1 M NaOH, and 1 M HCl were analyzed. Dissolution was determined from the increase in anion resin (AER)–, NaHCO₃‐, and NaOH‐extractable P in soil amended with PR compared with the control soil. Where P was applied, resin P significantly increased above the no‐P treatment. Busumbu‐PR solubility was low and did not increase significantly in 16 weeks. Anion + cation (ACER)‐extractable P was generally greater than AER‐P. The difference was greater for PR than for triple superphosphate (TSP). The ACER extraction may be a better estimate of plant P availability, particularly when poorly soluble P sources are used. Addition of P fertilizers alone or in combination with Tithonia diversifolia (TSP, BPR, TSP + Tithonia, and BPR + Tithonia) increased the concentration of labile inorganic P pools (NaHCO₃‐ and NaOH‐P_i). Cumulative evolved CO₂ was significantly correlated with cumulative N mineralized from Tithonia (r, 0.51, p < 0.05). Decrease in pH caused NH ‐N accumulation while NO ‐N remained low where Tithonia was incorporated at all sampling times. However, when pH was increased, NH ‐N declined with a corresponding rise in NO ‐N. Tithonia significantly depressed soil exchangeable acidity relative to control with time. A significant increase (p < 0.05) was observed for P uptake but not dry‐mass production in maize where BPR was applied. The variations in yield and P uptake due to source and rates of application were statistically significant. At any given P rate, highest yields were obtained with Tithonia alone. Combination of Busumbu PR with TSP or Tithonia did not enhance the effectiveness of the PR. The poor dissolution and plant P uptake of BPR may be related to the high Fe content in the PR material.  相似文献   

A Reviwe of: “Handbook of Forage and Rangeland Insects”     

Nancy L. Pelzer 《Journal Of Agricultural & Food Information》2013,14(3):266-267

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Book reviews     

B. Lamb  Jan Smeets  D. P. Ormrod  O. Preining  G. F. Humphrey  Clarence G. Golueke  Nancy M. Darrall  John C. Glaub  T. Viraraghavan 《Water, air, and soil pollution》1984,22(4):453-462

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Bioactive compounds of grapefruit (Citrus paradisi Cv. Rio Red) respond differently to postharvest irradiation, storage, and freeze drying     

Vanamala J  Cobb G  Turner ND  Lupton JR  Yoo KS  Pike LM  Patil BS 《Journal of agricultural and food chemistry》2005,53(10):3980-3985

In the present study, the effect of irradiation, storage, and freeze drying on grapefruit bioactive compounds was investigated. Grapefruits were exposed to one of two irradiation doses: 0 (control) or 300 Gy (137Cs, a proposed treatment against fruit flies) and then stored for up to 6 days. At the last storage time point (6 days after harvest), grapefruit pulp from control and irradiated fruits was freeze-dried. Bioactive compounds were extracted from Rio Red grapefruit pulp and analyzed with reverse phase liquid chromatography while volatile compounds were analyzed using gas chromatography. Freeze-dried pulp from irradiated fruits had a higher (P < or = 0.05) flavonoid content (naringin and narirutin) as compared to the freeze-dried pulp from the control fruits. Freeze-drying treatment reduced (P < or = 0.05) the lycopene content, but the reduction (P < or = 0.05) in beta-carotene content occurred only in the control fruit. Reduction in d-limonene and myrcene was observed in the irradiated fruits at 6 days after harvest and in the freeze-dried samples. These results warrant testing of the effect of postharvest treatments and processing on bioactive compounds in functional systems as they have varied effects on different bioactive compounds of grapefruit.  相似文献   

Mercury-Resistant Bacteria Associated With Macrophytes from A Polluted Lake     

Laurie F. Caslake  Skye S. Harris  Christine Williams  Nancy McCreary Waters 《Water, air, and soil pollution》2006,174(1-4):93-105

Although Onondaga Lake in the Syracuse NY area is contaminated with high levels of mercury from past manufacturing operations, macrophytes in the lake have been able to survive, apparently withstanding mercury toxicity. Homogenates of three macrophyte species, Myriophyllum spicatum L., Potamogeton crispus L., and Stuckenia pectinata (L.) Borner, were phenotypically positive for the presence of mercury resistant bacteria. As determined by PCR analysis, the mercury resistant bacteria associated with M. spicatum and S. pectinata also possessed merA, one of the more widely studied essential genes in the mer operon. Analysis of 24 macrophyte taxa isolated from lakes across the United States, as well as biological supply houses, showed that mercury resistant bacteria were associated with all macrophytes. One possible explanation for the association of mercury resistant bacteria with macrophytes is described. This hypothesis suggests that Hg ^r bacteria may potentially ameliorate the negative effects that mercury elicits in macrophytes.  相似文献   

Identification of puerarin and its metabolites in rats by liquid chromatography-tandem mass spectrometry   总被引：7，自引：0，他引：7  

Prasain JK  Jones K  Brissie N  Moore R  Wyss JM  Barnes S 《Journal of agricultural and food chemistry》2004,52(12):3708-3712

Puerarin (daidzein-8-C-glucoside) is the major bioactive isoflavone of kudzu root (the root of Pueraria lobata). Its metabolic fate, however, is not well-known. In this study, a sensitive and specific LC-ESI-MS/MS method for the determination of puerarin and its metabolites daidzein, dihydrodaidzein, and equol was developed for their analysis in biological samples. Two new metabolites of puerarin, mono- and dihydroxylated derivatives, were detected in the urine and feces of rats after oral administration. The persistence of puerarin in blood and urine as the principal metabolic form for the period of 4-72 h after oral administration suggested that puerarin is rapidly absorbed from the intestine without metabolism. Its presence in organs such as the brain suggests that this glucoside may enter tissues by specific transport pathways. Study of these metabolites may provide further understanding of the health beneficial effects of puerarin in kudzu dietary supplements.  相似文献   

Canopy leaching of cations in Central European forest ecosystems – a regional assessment     

Jens‐Johann Langusch  Werner Borken  Martin Armbruster  Nancy B. Dise  Egbert Matzner 《植物养料与土壤学杂志》2003,166(2):168-174

The leaching of Ca, Mg, and K from canopies is a major pathway of these cations into forest soils. Our aim was to quantify rates of canopy leaching and to identify driving factors at the regional scale using annual fluxes of bulk precipitation and throughfall from 37 coniferous and deciduous forests of North and Central Europe. Total deposition of Ca, Mg, K, and H⁺ was estimated with Na as an index cation. The median canopy leaching increased in the order: Mg (0.11 kmol_c ha^–1 a^–1) < Ca (0.31 kmol_c ha^–1 a^–1) < K (0.39 kmol_c ha^–1 a^–1). Canopy leaching of Ca and K was positively correlated with the calculated total H⁺ deposition and H⁺ buffered in the canopy, whereas canopy leaching of Mg was not. With contrasting effects, fluxes of SO₄‐S and NH₄‐N in throughfall explained to 64 % (P<0.001) of the Ca canopy leaching. Fluxes of NH₄‐N and Ca were negatively correlated, suggesting that buffering of H⁺ by NH₃ deposition reduced canopy leaching of Ca. Amount of bulk precipitation and SO₄‐S in throughfall were identified as much weaker driving factors for canopy leaching of K (r²=0.28, P<0.01). Our results show that Ca is the dominant cation in buffering the H⁺ input in the canopy. At the regional and annual scale, canopy leaching of Mg appears to be unaffected by H⁺ deposition and H⁺ buffering in the canopy.  相似文献   

Potential importance of bacteria and fungi in nitrate assimilation in soil     

David D. Myrold  Nancy Ritchie Posavatz 《Soil biology & biochemistry》2007,39(7):1737-1743

Soil microorganisms can use a wide range of N compounds but are thought to prefer NH₄⁺. Nevertheless, ¹⁵N isotope dilution studies have shown that microbial immobilization of NO₃⁻ can be an important process in many soils, particularly relatively undisturbed soils. Our objective was to develop a method for measuring NO₃⁻ immobilization potential so that the relative contributions of bacteria and fungi could be determined. We modified and optimized a soil slurry method that included amendments of KNO₃, glucose, and methionine sulfoximine (an inhibitor of N assimilation) in the presence of two protein synthesis inhibitors: chloramphenicol, which inhibits bacteria, or cycloheximide, which inhibits fungi. By adding ¹⁵N-labeled KNO₃, we were able to measure gross rates of NO₃⁻ production (i.e., gross nitrification) and consumption (i.e., gross NO₃⁻ immobilization). We found that bacteria, not fungi, had the greatest potential for assimilating, or immobilizing, NO₃⁻ in these soils. This is consistent with their growth habit and distribution in the heterogeneous soil matrix.  相似文献