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81.
Exocrine pancreatic function was evaluated in 13 dogs, using the chymotrypsin-labile peptide N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA). This peptide releases p-aminobenzoic acid (PABA) in the presence of pancreatic chymotrypsin. The amount of PABA in blood or urine after BT-PABA administration then served as an index of pancreatic function. Similarly, a xylose absorption test has been described in the literature to evaluate absorptive function of the small intestine. Here, the pentose sugar d(+)xylose was given orally, and blood xylose concentrations were then measured at intervals. Since both tests were performed in nearly the same way, they were combined into a single test. A solution containing BT-PABA (30 mg/ml) and xylose (100 mg/ml) was administered perorally to dogs with and without pancreatic duct ligation. In the unoperated (control) dogs, peak blood concentrations for PABA occurred between 60 and 120 minutes and xylose concentrations were maximal between 30 and 90 minutes. Pancreatic duct ligation reduced PABA concentrations at 90 minutes to one-sixth of the values in control dogs. Xylose absorption, however, was not altered by pancreatic duct ligation. In this way, digestive and absorptive functions were both evaluated, using a single 90-minute test. 相似文献
82.
Schober KE Stern JA DaCunha DN Pedraza-Toscano AM Shemanski D Hamlin RL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(3):578-585
BACKGROUND: Congestive heart failure (CHF) is a common clinical syndrome characterized by elevated filling pressure. HYPOTHESIS: Doppler echocardiographic (DE) variables of left ventricular (LV) filling can predict a decline of LV end-diastolic pressure (LVEDP) induced by acute preload reduction in dogs with compensated CHF. ANIMALS: Five male hound dogs. METHODS: Dogs previously instrumented with a transvenous cardiac pacemaker and a LV pressure gauge were paced at 160-180 bpm to induce mild CHF characterized by LVEDP > 20 mmHg. LVEDP and 9 DE variables of LV filling derived from diastolic time intervals, transmitral and pulmonary venous flow, and tissue Doppler imaging were measured simultaneously at baseline and 30, 60, 120, and 240 minutes after furosemide (4 mg/kg, IV) or placebo (0.9% saline, IV). Repeated measures analysis of variance and correlation analysis were used to determine the association between the decline of LVEDP after furosemide and DE measures of LV filling pressure (LVFP). RESULTS: Furosemide but not placebo decreased LVEDP (P < .001). The ratio of early transmitral flow velocity to LV isovolumic relaxation time (E : IVRT) predicted LVEDP best (R(2)= .50; P < .001). Correlations were also found between LVEDP and IVRT, E, ratio between E and late diastolic transmitral flow velocity (E : A), and early diastolic velocity of the mitral annulus (Ea). The ratio of E to Ea (E : Ea) was not useful in the prediction of LVEDP in this model. CONCLUSION AND CLINICAL IMPORTANCE: E : IVRT can be used to predict LVFP in dogs with mild left-sided CHF induced by rapid pacing. 相似文献
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Schober KE Bonagura JD Scansen BA Stern JA Ponzio NM 《American journal of veterinary research》2008,69(8):1034-1049
OBJECTIVE: To identify Doppler echocardiographic (DE) variables that correlate with left ventricular filling pressure (LVFP). ANIMALS: 7 healthy dogs (1 to 3 years old). PROCEDURES: Dogs were anesthetized and instrumented to measure left atrial pressure (LAP), left ventricular pressures, and cardiac output. Nine DE variables of LVFP derived from diastolic time intervals, transmitral and pulmonary venous flow, and tissue Doppler images were measured over a range of hemodynamic states induced by volume loading and right atrial pacing. Associations between simultaneous invasive measures of LVFP and DE measures of LVFP were determined by use of regression analysis. Receiver operating characteristic analysis was used to predict increases in mean LAP on the basis of DE variables. RESULTS: Mean LAP was correlated with several DE variables: the ratio between peak velocity during early diastolic transmitral flow and left ventricular isovolumic relaxation time (peak E:IVRT) during sinus rhythm and during right atrial pacing, IVRT, the ratio between late diastolic transmitral flow velocity and pulmonary venous flow duration, and the interval between onset of early diastolic mitral annulus motion and onset of early diastolic transmitral flow. Cutoff values of 2.20 and 2.17, for peak E:IVRT in dogs with sinus rhythm and atrial pacing predicted increases in mean LAP (> or = 15 mm Hg) with sensitivities of 90% and 100% and specificities of 92% and 100%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Doppler echocardiography can be used to predict an increase in LVFP in healthy anesthetized dogs subjected to volume loading. 相似文献
85.
C.S.T. Daughtry P.C. Doraiswamy E.R. Hunt Jr. A.J. Stern J.E. McMurtrey III J.H. Prueger 《Soil & Tillage Research》2006,91(1-2):101-108
Management of plant litter or crop residues in agricultural fields is an important consideration for reducing soil erosion and increasing soil organic C. Current methods of quantifying crop residue cover are inadequate for characterizing the spatial variability of residue cover within fields or across large regions. Our objectives were to evaluate several spectral indices for measuring crop residue cover using satellite multispectral and hyperspectral data and to categorize soil tillage intensity in agricultural fields. Landsat Thematic Mapper (TM) and EO-1 Hyperion imaging spectrometer data were acquired over agricultural fields in central Iowa in May and June 2004. Crop residue cover was measured in corn (Zea mays L.) and soybean (Glycine max Merr.) fields using line-point transects. Spectral residue indices using Landsat TM bands were weakly related to crop residue cover. With the Hyperion data, crop residue cover was linearly related to the cellulose absorption index (CAI), which measures the relative intensity of cellulose and lignin absorption features near 2100 nm. Coefficients of determination (r2) for crop residue cover as a function of CAI were 0.85 for the May and 0.77 for the June Hyperion data. Three tillage intensity classes, corresponding to intensive (<15% residue cover), reduced (15–30% cover) and conservation (>30% cover) tillage, were correctly identified in 66–68% of fields. Classification accuracy increased to 80–82% for two classes, corresponding to conventional (intensive + reduced) and conservation tillage. By combining information on previous season's (2003) crop classification with crop residue cover after planting in 2004, an inventory of soil tillage intensity by previous crop type was generated for the whole Hyperion scene. Regional surveys of soil management practices that affect soil conservation and soil C dynamics are possible using advanced multispectral or hyperspectral imaging systems. 相似文献
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S-L Lee BM Kumar J-G Kim S-A Ock B-G Jeon S Balasubramanian S-Y Choe G-J Rho 《Reproduction in domestic animals》2007,42(1):44-52
The present study compared the efficiency of transgenic (TG) cloned embryo production by somatic cell nuclear transfer (SCNT) with fetal-derived fibroblast cells (FFCs) which were transfected with pEGFP-N1 to in vitro-fertilized (IVF), parthenogenetic and SCNT counterparts by evaluating the rates of cleavage and blastocyst formation, apoptosis rate at different developmental stages, cell number, ploidy and gene expression in blastocysts. In SCNT and TG embryos, the rates of cleavage and blastocyst formation were significantly lower (p < 0.05) than those of IVF controls, but it did not differ between SCNT and TG embryos. In IVF control, 86.7% embryos displayed diploid chromosomal complements and the rates were significantly (p < 0.05) higher than those of SCNT and TG embryos. Most TG embryos (79%) with FFCs expressed the gene by both PCR and under fluorescence microscopy. The expression of apoptosis by TUNEL was first detected at six to eight cell stages in all embryos of IVF, SCNT and TG groups, but the expression rate at each developmental stages was significantly higher (p < 0.05) in SCNT and TG embryos than in IVF counterparts. The expression rate in inner cell mass (ICM) of TG embryos was significantly higher (p < 0.05) than in SCNT and IVF embryos. These results indicate that the high occurrence of apoptosis observed in SCNT and TG embryos compared with IVF counterparts might influence the developmental competence. Moreover, the SCNT embryos derived using non-transfected donor cells exhibited a lower apoptosis expression in ICM cells than in TG embryos derived using pEGP-N1-transfected donor cells suggesting a possible role of negative gene effect in TG embryos. 相似文献
89.
Prelinguistic infants recognized structural correspondences in acoustic and optic properties of synchronized, naturally spoken disyllables, but did so only when they were looking to their right sides. This result suggests that intermodal speech perception is facilitated by rightward orientation of attention and subserved by the left hemisphere. 相似文献
90.