Response of susceptible and resistant peach-potato aphids Myzus persicae (Sulz.) to insecticides in leaf-dip bioassays     

Roman M. Sawicki  Adrian D. Rice 《Pest management science》1978,9(6):513-516

The response of susceptible (S), moderately resistant (R₁) and strongly resistant (R₂) peach-potato aphids, Myzus persicae (Sulz.) to organophosphorus, carbamate and pyrethroid insecticides was tested by a leaf-dip bioassay. The aphids were placed on potato leaves (dipped in insecticide solutions 1–2 or 24 h before infestation) and their mortality examined 48 h later. R₁ aphids were virtually susceptible to most of the carbamates, demephion and acephate, but were slightly to moderately resistant (2.1–9.4 times) to permethrin, cypermethrin and (S)-α-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate (I), (NRDC 161), to 5,6,7,8-tetrahydro-2-methylquinolin-4-yl dimethylcarbamate (II), (Hoechst 25 682) and demeton-S-methyl. R₂ aphids resisted more strongly or very strongly (between 65 and 1280 times) the pyrethroids, demeton-S-methyl (×94), II (×83) and demephion (×9), and were slightly to moderately (2–5 times) resistant to acephate, pirimicarb, ethiofencarb and 2-(dimethylcarbamoyloxyimino)-3-methoxyimino-N,N- dimethylbutyramide (III), (DPX 3853). Both resistant strains were susceptible to nitrilacarb [4,4-dimethyl-5-(methylcarbamoyloxyimino)pentanenitrile] complex (1:1) with zinc chloride (IV), (AC 85 258). The implications of these results in terms of practical aphid control are discussed.  相似文献   

Modifiers of gastrointestinal motility of cattle.     

Adrian Steiner 《Veterinary Clinics of North America: Food Animal Practice》2003,19(3):647-660

Little clinically relevant, evidence-based data about the effect of motility modifiers on the GI tract of cattle are currently available. Additionally, some of the published results seem to be contradictory. Three main facts explain this apparent discrepancy: (1) Results may not be transferred from one species to another, because presence, concentration, location, distribution, and function of specific receptors may differ significantly among species. (2) The lack of a significant effect on smooth muscle preparations in vitro does not necessarily exclude a certain drug's motility-modifying property on affected animals in vivo. Certain drugs bind to receptors outside the myenteric plexus. Others, such as lidocaine and adrenergic-, dopaminergic-, and opioid-antagonists increase only GI motility, if inhibitory reflexes or a hyperactive state of the inhibitory sympathetic nervous system preexists. (3) Effects of motility modifiers as found in healthy experimental animals in vivo may not be similar to those found in spontaneously diseased animals. Accurate and reliable data on the effect of modifiers of GI motility of cattle will be obtained only from double-blinded, evidence-based, in vivo studies on spontaneously affected animals. Because well-documented results from such studies are extremely rare, intensive research in this field is warranted in the future.  相似文献   

Serum troponin I levels in hyperthyroid cats before and after treatment with radioactive iodine     

Connolly DJ  Guitian J  Boswood A  Neiger R 《Journal of Feline Medicine and Surgery》2005,7(5):289-300

A raised concentration of serum cardiac troponin I (cTnI) is a sensitive marker of cardiac myocyte injury in the cat and assays developed for its measurement in human patients have been validated in the cat. Raised levels have been associated with a number of cardiac insults including hypertrophic cardiomyopathy and trauma. Hyperthyroidism is a common disease of older cats and excess thyroid hormone is known to produce significant cardiovascular effects in this species. This study evaluated the effect of treatment for hyperthyroidism with radioactive iodine on cTnI concentration, assessed the association between thyroxin levels and glomerular filtration rate (GFR) and cTnI concentration in cats treated for hyperthyroidism and described changes in echocardiographic parameters following treatment. Prior to the treatment serum cTnI was measured and echocardiography performed, thyroxin, cTnI, and echocardiography were then repeated at various time points following radioisotope therapy. The results show that higher thyroxin levels were significantly (P=0.002) associated with a higher likelihood of the cat presenting with detectable levels of cTnI. No significant association was found between GFR and presence of detectable levels of cTnI. Furthermore the results indicate that the effects of hyperthyroidism on echocardiographic parameters appear considerably less in this study than in previous studies and that the main outcome of treatment on these parameters is a significant reduction in fractional shortening (P=0.006). These results suggest that chronic exposure to excess thyroid hormone may induce myocyte damage of sufficient severity to raise serum cTnI concentration in a proportion of cats that resolves following establishment of a euthyroid state.  相似文献   

Evolution and revolution     

Boswood A 《The Journal of small animal practice》2005,46(3):113-114

  相似文献   

Induced resistance for plant disease control: maximizing the efficacy of resistance elicitors     

Walters D  Walsh D  Newton A  Lyon G 《Phytopathology》2005,95(12):1368-1373

ABSTRACT Plants can be induced to develop enhanced resistance to pathogen infection by treatment with a variety of abiotic and biotic inducers. Biotic inducers include infection by necrotizing pathogens and plant-growth-promoting rhizobacteria, and treatment with nonpathogens or cell wall fragments. Abiotic inducers include chemicals which act at various points in the signaling pathways involved in disease resistance, as well as water stress, heat shock, and pH stress. Resistance induced by these agents (resistance elicitors) is broad spectrum and long lasting, but rarely provides complete control of infection, with many resistance elicitors providing between 20 and 85% disease control. There also are many reports of resistance elicitors providing no significant disease control. In the field, expression of induced resistance is likely to be influenced by the environment, genotype, and crop nutrition. Unfortunately, little information is available on the influence of these factors on expression of induced resistance. In order to maximize the efficacy of resistance elicitors, a greater understanding of these interactions is required. It also will be important to determine how induced resistance can best fit into disease control strategies because they are not, and should not be, deployed simply as "safe fungicides". This, in turn, will require information on the interaction of resistance elicitors with crop management practices such as appropriate-dose fungicide use.  相似文献   

Cardiovascular and respiratory effects of ketamine infusions in isoflurane-anesthetized dogs before and during noxious stimulation   总被引：1，自引：0，他引：1  

Boscan P  Pypendop BH  Solano AM  Ilkiw JE 《American journal of veterinary research》2005,66(12):2122-2129

OBJECTIVE: To characterize the effects of ketamine administration on the cardiovascular and respiratory systems and on acid-base balance and to record adverse effects of ketamine in isoflurane-anesthetized dogs. ANIMALS: 6 healthy adult mongrel dogs. PROCEDURE: Dogs were anesthetized with isoflurane (1.25 times the individual minimum alveolar concentration) in oxygen, and ketamine was administered IV to target pseudo-steady-state plasma concentrations of 0, 0.5, 1, 2, 5, 8, and 11 microg/mL. Isoflurane concentration was reduced to an equipotent concentration. Cardiovascular, respiratory, and acid-base variables; body temperature; urine production; and adverse effects were recorded before and during noxious stimulation. Cardiac index, stroke index, rate-pressure product, systemic vascular resistance index, pulmonary vascular resistance index, left ventricular stroke work index, right ventricular stroke work index, arterial oxygen concentration, mixed-venous oxygen concentration, oxygen delivery, oxygen consumption, oxygen extraction ratio, alveolar-arterial oxygen partial pressure gradient, and venous admixture were calculated. Plasma ketamine and norketamine concentrations were measured. RESULTS: Overall, ketamine administration improved ventilation, oxygenation, hemodynamics, and oxygen delivery in isoflurane-anesthetized dogs in a dosedependent manner. With the addition of ketamine, core body temperature was maintained or increased and urine production was maintained at an acceptable amount. However, at the higher plasma ketamine concentrations, adverse effects such as spontaneous movement and profuse salivation were observed. Myoclonus and dysphoria were observed during recovery in most dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Infusion of ketamine appears to be a suitable technique for balanced anesthesia with isoflurane in dogs. Plasma ketamine concentrations between 2 to 3 microg/mL elicited the most benefits with minimal adverse effects.  相似文献   

Expression patterns of chicken Toll-like receptor mRNA in tissues, immune cell subsets and cell lines   总被引：2，自引：0，他引：2  

Iqbal M  Philbin VJ  Smith AL 《Veterinary immunology and immunopathology》2005,104(1-2):117-127

  相似文献   

Electrogoniometric analysis of equine metacarpophalangeal joint lameness     

M Adrian  B Grant  M Ratzlaff  J Ray  C Boulton 《American journal of veterinary research》1977,38(4):431-435

Electrogoniometry was used qualitively and quantitatively to assess the movements of the normal and pathologic metacarpophalangeal joints of selected horses. A total of 4 Thoroughbreds, 1 normal and 3 with clinical and radiographic changes in the metacarpophalangeal joints of 1 limb, were evaluated at the walk and trot. Goniograms of the affected joints were compared with those of the normal horse and the normal contralateral metacarpophangeal joint. Qualitative asymmetry was recognized on the goniograms, and the ranges of motion were quantified and related to the clinical and radiologic observations.  相似文献   

Quantitative evaluation of equine carpal lamenesses     

Marc H. Ratzlaff  Barrie D. Grant  Marlene Adrian 《Journal of Equine Veterinary Science》1982,2(3):78-88

  相似文献   

Reply to V. Chour's note on a heuristic model of soil water regimes in clay soils in the presence of mole drainage     

Adrian C. Armstrong 《Agricultural Water Management》1984,9(2):158-164

  相似文献