Cardiovascular effects of the macrolide antibiotic tilmicosin, administered alone and in combination with propranolol or dobutamine, in conscious unrestrained dogs   总被引：3，自引：1，他引：2  

B. W. MAIN  J. R. MEANS  L. E. RINKEMA  W. C. SMITH  R. D. SARAZAN 《Journal of veterinary pharmacology and therapeutics》1996,19(3):225-232

Tilmicosin(TM), a macrolide antibiotic and active ingredient in formulated Micotil 300^TM (Eli Lilly and Co., Indianapolis, IN, USA), is the active ingredient in a formulated animal product used for the treatment of respiratory tract infections in cattle. Owing to the concern of governmental regulatory agencies over the possibility of an accidental injection of the antibiotic to a livestock handler, the cardiovascular effects of sub lethal doses of TM were evaluated in conscious mixed-breed dogs. Left ventricular function, systemic arterial blood pressure, and heart rate (HR) responses to TM alone and in combination with propranolol(P) or dobutamine HCl(DOB) were evaluated. Dogs were instrumented with indwelling micromanometers implanted in the left ventricular chamber and in the thoracic aorta. Cardiovascular variables were recorded, and the peak value of the first derivative of left ventricular pressure (dp/dt_(max)) was used as an index of left ventricular inotropic state. Six treatments were randomly assigned to each of the six dogs using a Latin square design. The six treatments were vehicle, TM alone (2.5 mg/kg of body weight), TM immediately followed by P. and TM immediately followed by 1 of 3 dosages of DOB infused for ?45 min. Additionally, doses of TM alone (0.25, 1.0, 2.5, and 5.0 mg/kg) were administered to complete a dose-response curve. TM caused dose dependent decreases in (dp/dt_(max)) and aortic pulse pressure. HR increased dose-dependently. Left ventricular end-diastolic pressure increased at the 2.5 and 5.0 mg/kg dosages. Left ventricular systolic pressure was reduced dose-dependently at the 2.5 and 5.0 mg/kg dosages. Treatment with P exacerbated the negative inotropic effect and the decrease in left ventricular systolic pressure, but did not attenuate the tachycardia associated with TM treatment. DOB attenuated the changes in ventricular inotropic state in a dose-dependent manner. DOB infusion also restored left ventricular systolic pressure at dosages of 3 or 10 μg/min/kg. Our data indicate that toxic doses of TM may have a negative inotropic effect in conscious dogs. HR increased in a dose-dependent manner and was not the result of β₁-receptor stimulation. DOB reversed some, but not all, of the effects caused by TM administration.  相似文献   

Mechanical Properties of Four Suture Patterns for Transected Equine Tendon Repair     

K. J. EASLEY DVM  MS    T. S. STASHAK DVM  MS  DiplomateACVS    F. W. SMITH PhD  G. VAN SLYKE BVSC 《Veterinary surgery : VS》1990,19(2):102-106

Thirty-six superficial digital flexor tendons from nine fresh equine cadavers were transected and sutured with size 2 monofilament nylon. Nine tendons were repaired with each of four suture patterns: single-locking loop, double-locking loop, triple-locking loop, or three-loop pulley. The times required for application, tensile strengths, resistance to distraction (gap), and modes of failure were analyzed. The mean times required were: single-locking loop, 3 mins, 15 secs; double-locking loop, 4 mins, 15 secs; triple-locking loop, 10 mins, 50 secs; and three-loop pulley, 4 mins. The double-locking loop, triple-locking loop, and three-loop pulley suture patterns were stronger than the single-locking loop. The triple-locking loop and three-loop pulley patterns were close in strength and only the triple-locking loop was stronger than the double-locking loop. The three-loop pulley had the greatest resistance to gap formation and its mode of failure was different from the others. The three-locking loop suture patterns failed by suture breakage but the three-loop pulley failed first by suture pull-out and then by suture breakage.  相似文献   

WEATHERING OF SOME SCOTTISH BASIC IGNEOUS ROCKS WITH REFERENCE TO SOIL FORMATION     

WILMA W. SMITH 《European Journal of Soil Science》1962,13(2):202-215

  相似文献   

THE REACTION OF FLUORIDE WITH SOILS AND SOIL MINERALS   总被引：4，自引：0，他引：4  

K. W. PERROTT  B. F. L. SMITH  R. H. E. INKSON 《European Journal of Soil Science》1976,27(1):58-67

The reaction of sodium fluoride solution with soils and soil minerals at constant pH has been assessed as a possible single-value characteristic in the classification of soils, particularly those containing significant amounts of poorly ordered inorganic material. A suitable method involves reaction of the soil or clay at 25°C with 0·85 M sodium fluoride at pH 6·8, the amount of OH^? released after 25 min being taken as the single-value characteristic. There was a statistically significant correlation between the amount of OH^? released and the amount of alumina extracted with cold 5 per cent sodium carbonate solution from both freely drained and poorly drained Scottish soils. The multiple correlation coefficients were improved for freely drained soils by including the dithionite-extracted ferric oxide and the silica soluble in 5 per cent sodium carbonate solution. The procedure is not suitable for surface soils, because of interference by organic matter, or for carbonate-containing soils unless carbonate is removed.  相似文献   

Effects of organic and inorganic calcium compounds on soil-solution pH and aluminium concentration     

C. J. SMITH  K. M. GOH  W. J. BOND  J. R. FRENEY† 《European Journal of Soil Science》1995,46(1):53-63

The reactions of two organic (citrate and fulvate) and two inorganic (chloride and phosphogypsum) calcium compounds were studied during leaching of columns of unsaturated acidic soil. The potential of these compounds to decrease the aluminium concentration in the soil solution and remove exchangeable aluminium, and their effects on soil acidity are described. The calcium citrate solution increased the soil solution pH from 5 to a maximum value of 7 in the upper portion of the column. In contrast, the fulvate, calcium chloride and phosphogypsum solutions had little effect on soil-solution pH. Treatment with calcium citrate, or fulvate solution that contained 51 mm Na, removed most of the exchangeable aluminium from the column. The cation exchange sites in the upper portion of the column were saturated with calcium, and the cation exchange capacity of the soil was increased from 35 to c. 80 mmol_c kg^?1 in the calcium citrate treatment. Leachate from this treatment contained low (< 2 mm ) calcium concentrations and high aluminium concentrations. In contrast, the above changes were not shown by the calcium chloride and phosphogypsum treatments. In these treatments the calcium concentration in the leachate was equal to that in the inflowing solution, which indicated that calcium was transported through the entire column. These results suggest that calcium alone was ineffective in displacing aluminium from the cation exchange sites and a strong complexing agent such as citrate or fulvate is needed to mobilize the exchangeable aluminium.  相似文献   

Extending the range of dose-effect curves for irradiated mice     

SMITH WW  CORNFIELD J 《Science (New York, N.Y.)》1958,128(3322):473-474

  相似文献   

An approach to quantifying various types of spontaneous activity     

SMITH OA  DEVITO JL 《Science (New York, N.Y.)》1959,129(3357):1229-1231

The output of an activity-measuring device is fed into low- and high-gain cumulative recorder channels which are reset to zero after different time periods. The records, inscribed at various paper speeds, are easily quantified. The tracing patterns can be identified with specific activities of undisturbed animals. The activities are monitored by means of closed-circuit television.  相似文献   

Use of sulfuric acid-dichromate mixture in cleaning glassware     

HENRY RJ  SMITH EC 《Science (New York, N.Y.)》1946,104(2705):426-427

  相似文献   

Surface phagocytosis; its relation to the mechanism of recovery in pneumococcal pneumonia     

WOOD WB  SMITH MR  WATSON B 《Science (New York, N.Y.)》1946,104(2689):28-29

  相似文献   

Acanthamoeba: observations on animal pathogenicity     

CULBERTSON CG  SMITH JW  MINNER JR 《Science (New York, N.Y.)》1958,127(3313):1506

  相似文献