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81.
82.
Hoenig M Alexander S Holson J Ferguson DC 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(5):529-532
Intravenous glucose tolerance tests (IVGTTs) are used in cats and other species to assess insulin sensitivity. Several dosages have been reported but the dosage that maximally stimulates insulin secretion in cats has not been determined nor has it been compared in lean and obese animals. IVGTTs were performed in 4 lean and 4 obese spayed female cats with 5 glucose dosages: 0.3 (A), 0.5 (B), 0.8 (C), 1.0 (D). and 1.3 (E) g/kg body weight (BW). Each cat received each dosage in a random design. The glucose disposal rate was significantly different only between lean and obese cats at the highest glucose dosage. The area under the curve for insulin increased significantly among A, B, C, and D in lean and among A, B, and C in obese cats but not between D and E in lean and among C, D, and E in obese cats. Baseline insulin secretion was significantly higher (P = .03) and 1st peak insulin secretion was approximately 50% lower in obese as compared to lean cats (P = .03). Lean but not obese cats reached baseline insulin concentrations at all dosages at 120 minutes. We conclude that the glucose dosage for maximal insulin secretion is 1.0 g/ kg BW in lean and 0.8 g/kg BW in obese cats, supporting routine use of 1 g/kg BW to maximally stimulate insulin secretion regardless of body composition. Obese cats showed an abnormal insulin secretion pattern, indicating a defect in insulin secretion with obesity and insulin resistance. 相似文献
83.
84.
Ajwa HA Trout T Mueller J Wilhelm S Nelson SD Soppe R Shatley D 《Phytopathology》2002,92(12):1349-1355
ABSTRACT Strawberry fields in California (9,500 ha annually) are pre-plant fumigated with methyl bromide and chloropicrin to prevent serious soil pest and disease problems. Although soil fumigation with methyl bromide has ensured stability of strawberry production, its use is being discontinued because of its effect on stratospheric ozone. The likely short-term alternatives such as 1,3-dichloropropene, chloropicrin, and metham sodium, although not ozone depleters, are potentially hazardous to the environment and humans if applied improperly. Water-soluble formulations of alternative fumigants can be applied through drip irrigation systems established to irrigate crops. In comparison to conventional shank methods of injection, application of soluble formulations through drip irrigation systems would be economical and environmentally friendly, reduce worker exposure, and allow for simultaneous or sequential application of a combination of fumigants. This paper discusses techniques developed to apply alternative fumigants through drip irrigation systems, and reviews ongoing studies to determine optimum application rates, soil conditions, plastic mulches, and amount of irrigation water used to apply these alternative fumigants. 相似文献
85.
86.
Murray AG 《Pest management science》2002,58(6):585-594
Sea lice are ectoparasites of salmonids that have been associated with the recent decline in sea trout numbers in north-west Europe. Observed patterns of louse load distribution between sea trout in the seas surrounding the UK, Ireland and Norway and a simple model have been used to analyse the epidemiology of lice. Loads are aggregated and deviate strongly from the Poisson distribution, although less than is observed with many other parasites. The louse numbers on fish from offshore sites are slightly less variable than for fish from coastal sites with comparable mean loads. Analysis of louse development stages and sexes shows that selection between hosts by sea lice plays a limited role. If host selection is absent, then associated poor condition would be caused by, not the cause of, high louse burdens; however the absence of such selection is not proved. Scenarios with infection that is patchy in space and time best generate the aggregated load patterns observed; these patches accord with observed swarms of copepodids. Prevalence patterns may indicate the movement of trout between environments. Control of copepodids in infection 'hot spots', either directly or through control of louse egg production in their catchment, may reduce louse loads on wild sea trout and, in particular, extreme and damaging loads. 相似文献
87.
Thyroid function and serum hepatic enzyme activity in dogs after phenobarbital administration 总被引:2,自引:0,他引:2
Gieger TL Hosgood G Taboada J Wolfsheimer KJ Mueller PB 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2000,14(3):277-281
Phenobarbital is the drug of choice for control of canine epilepsy. Phenobarbital induces hepatic enzyme activity, can be hepatotoxic, and decreases serum thyroxine (T4) concentrations in some dogs. The duration of liver enzyme induction and T4 concentration decreases after discontinuation of phenobarbital is unknown. The purpose of this study was to characterize the changes in serum total T4 (TT4), free T4 (FT4), thyroid-stimulating hormone (TSH), cholesterol and albumin concentrations, and activities in serum of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) after discontinuation of long-term phenobarbital administration in normal dogs. Twelve normal dogs were administered phenobarbital at a dosage of approximately 4.4-6.6 mg/kg PO q12h for 27 weeks. Blood was collected for analysis before and after 27 weeks of phenobarbital administration and then weekly for 10 weeks after discontinuation of the drug. The dogs were clinically normal throughout the study period. Serum ALT and ALP activity and TSH and cholesterol concentrations were significantly higher than baseline at week 27. Serum T4 and FT4 were significantly lower. Serum albumin and GGT were not changed from baseline at week 27. Changes in estimate of thyroid function (TT4, FT4, TSH) persisted for 1-4 weeks after discontinuation of phenobarbital, whereas changes in hepatic enzyme activity (ALT, ALP) and cholesterol concentration resolved in 3-5 weeks. To avoid false positive results, it is recommended that thyroid testing be performed at least 4 weeks after discontinuation of phenobarbital administration. Elevated serum activity of hepatic enzymes 6-8 weeks after discontinuation of phenobarbital may indicate hepatic disease. 相似文献
88.
Jessica D Lightsey Sentiel A Rommel Alexander M Costidis Thomas D Pitchford 《Journal of zoo and wildlife medicine》2006,37(3):262-275
Between 1993 and 2003, 713 (24%) of 2,940 dead Florida manatees (Trichechus manatus latirostris) recovered from Florida waters and examined were killed by watercraft-induced trauma. It was determined that this mortality was the result of watercraft trauma because the external wound patterns and the internal lesions seen during gross necropsy are recognizable and diagnostic. This study documents the methods used in determining watercraft-related mortality during gross necropsy and explains why these findings are diagnostic. Watercraft can inflict sharp- and blunt-force trauma to manatees, and both types of trauma can lead to mortality. This mortality may be a direct result of the sharp and blunt forces or from the chronic effects resulting from either force. In cases in which death is caused by a chronic wound-related complication, the original incident is usually considered to be the cause of death. Once a cause of death is determined, it is recorded in an extensive database and is used by Federal and state managers in developing strategies for the conservation of the manatee. Common sequelae to watercraft-induced trauma include skin lesions, torn muscles, fractured and luxated bones, lacerated internal organs, hemothorax, pneumothorax, pyothorax, hydrothorax, abdominal hemorrhage and ascites, and pyoperitoneum. 相似文献
89.
Ariena H. C. van Bruggen Alexander M. Semenov Anne D. van Diepeningen Oscar J. de Vos Wim J. Blok 《European journal of plant pathology / European Foundation for Plant Pathology》2006,115(1):105-122
A healthy soil is often defined as a stable soil system with high levels of biological diversity and activity, internal nutrient
cycling, and resilience to disturbance. This implies that microbial fluctuations after a disturbance would dampen more quickly
in a healthy than in a chronically damaged and biologically impoverished soil. Soil could be disturbed by various processes,
for example addition of a nutrient source, tillage, or drying-rewetting. As a result of any disturbance, the numbers of heterotrophic
bacteria and of individual species start to oscillate, both in time and space. The oscillations appear as moving waves along
the path of a moving nutrient source such as a root tip. The phase and period for different trophic groups and species of
bacteria may be shifted indicating that succession occurs. DGGE, Biolog and FAME analysis of subsequent populations in oscillation
have confirmed that there is a cyclic succession in microbial communities. Microbial diversity oscillates in opposite direction
from oscillations in microbial populations. In a healthy soil, the amplitudes of these oscillations will be small, but the
background levels of microbial diversity and activity are high, so that soil-borne diseases will face more competitors and
antagonists. However, soil-borne pathogens and antagonists alike will fluctuate in time and space as a result of growing plant
roots and other disturbances, and the periods and phases of the oscillations may vary. As a consequence, biological control
by members of a single trophic group or species may never be complete, as pathogens will encounter varying populations of
the biocontrol agent on the root surface. A mixture of different trophic groups may provide more complete biological control
because peaks of different trophic groups occur at subsequent locations along a root. Alternatively, regular addition of soil
organic matter may increase background levels of microbial activity, increase nutrient cycling, lower the concentrations of
easily available nutrient sources, increase microbial diversity, and enhance natural disease suppression. 相似文献
90.