The pharmacokinetics, metabolism and urinary detection time of etamiphylline in camels after intramuscular administration

The pharmacokinetics of etamiphylline were determined after an intramuscular (i.m.) dose of 3.5 mg/kg body weight in six healthy camels. Furthermore, the metabolites and drug detection time were evaluated. The data obtained median and (range) were as follows: the terminal elimination half-life (t(1/2 beta), h) was 3.04 (2.03-3.62); apparent total body clearance (Cl/F, L/h/kg) was 1.27 (0.74-2.99); the apparent volume of distribution at steady state (V(ss)/F, L/kg) was 4.94 (3.57-12.54); and renal clearance (Cl(r), L/h/kg) determined in two camels was 0.005 and 0.004, respectively. The detection time of etamiphylline in urine after an i.m. dose of 3.5 mg/kg body weight ranged between 12 and 13 days. Three etamiphylline metabolites were tentatively identified in camels urine: The first one desethyletamiphylline was the main metabolite and resulted from N-deethylation of etamiphylline had a molecular weight of 251, and was detected in urine for about 13-14 days. Theophylline (molecular weight 180) was the second metabolite and resulted from ring N-dealkylation of etamiphylline. It was present in small amounts and was detected for about 5 h after drug administration in urine. The third metabolite, possibly resulted from demethylation of etamiphylline, had a molecular weight of m/z 265, and was present in small amounts and was detected in urine for about 5 h after drug administration.     

Comparison of macrophage scavenger receptor-A knockout mice with wild type ones in the immune response against repeated infestation with Haemaphysalis longicornis

Using macrophage scavenger receptor-A knockout (SRKO) mice, we examined the role of macrophage class A scavenger receptors (MRS-A) on the immune response and acquisition of host resistance against repeated infestation with Haemaphysalis longicornis. Except for one batch of nymphs that infested one of the SRKO (SR-/-) mice and showed no appreciable reduction in body weight, all the other groups of nymphs manifested significant decrease in body weight. Both SR-/- and wild type (SR+/+) mice showed a sustained increase in anti-tick antibody titers, but SR+/+ mice showed significantly higher titers. The IFN-gamma assayed in SR-/- mouse immune sera was substantially less compared with that in SR+/+ mice. Immune sera from SR-/- and SR+/+ mice recognized the 51 and 44 kDa, and 44 kDa proteins, respectively, of the salivary gland antigen. The difference in the level of anti-tick resistance manifested by both groups of mice may be influenced by less efficient trapping and processing of tick antigens by macrophages in mice lacking for the macrophage scavenger receptors, and consequently affected the cascade of Th1 and Th2 responses. We have thus obtained valuable data that strongly infer the role of MSR-A in enhancing host defense against repeated infestation with H. longicornis.     

Effect of short periods of high incubation temperature on hatchability and incidence of embryo pathology of turkey eggs

1. Turkey eggs were incubated at 38.0 degrees and 38.5 degrees C at different stages of embryo development and for periods of 3 to 25 d. Results were compared with control eggs incubated at 37.5 degrees C. The age of mortality, the incidence of malpositions and the incidence of morphological abnormalities were recorded from all unhatched eggs. 2. Eggs incubated at 38.5 degrees C for 5 or more days hatched significantly less well than eggs incubated at 37.5 degrees C. Eggs incubated at 38.5 degrees C for 3 d hatched worse than controls but not significantly so. Eggs incubated between 0 and 25 d and 7 and 12 d but not between 0 and 6, 13 and 18 and 19 and 25 d, at 38.0 degrees C had significantly lower hatchabilities than eggs incubated at 37.5 degrees C. 3. Lowest hatchabilities were obtained when the eggs were incubated at high temperatures between 7 to 12 d and 6 to 10 d, indicating that embryos at this stage of development are more likely to succumb to high temperature than at other ages. 4. Increases in embryo mortality due to overheating were seen in weeks 3 and 4 of incubation and at the pipping stage. This was observed even when the period of overheating occurred in weeks 1 and 2 of incubation. 5. Embryos malpositioned with their head in the small end of the egg were seen at a higher incidence when overheating in the 2nd or 3rd quarter of the incubation period.     

Diagnostic features, confirmation and disease progression in 28 cases of lethal acrodermatitis of bull terriers

Lethal acrodermatitis (LAD) is a genetically determined metabolic disease of bull terriers first described in the USA in the 1980s. In this study, the largest so far reported, 28 bull terriers born in the UK were diagnosed as suffering from LAD, and the clinical findings and the progression of the disease with time are described. The main characteristics of LAD are stunting, splayed digits, eating difficulties, skin disease of the face and feet, and increased susceptibility to microbial infections. In older dogs, paronychia, nail disease and hyperkeratosis of the footpads develops, becoming severe in dogs over six months of age. A diagnosis of LAD can be strongly suspected in any bull terrier showing a combination of the aforementioned signs from an early age. Dermatohistopathological demonstration of marked parakeratotic hyperkeratosis is strongly supportive of the diagnosis of LAD and, in association with the typical clinical findings, is sufficient to confirm a diagnosis. Although many of the clinical signs and the pathology of this condition suggest zinc deficiency, the measurement of blood zinc levels as a diagnostic aid is of limited value.     

Adherence by Staphylococcus intermedius to canine keratinocytes in atopic dermatitis

The adherence of Staphylococcus intermedius to canine keratinocytes in normal dogs was compared to that in dogs suffering from atopic dermatitis, primary seborrhoea and bacterial pyoderma. Statistically significant greater adherence by S. intermedius to keratinocytes occurred in atopic dogs and dogs suffering from pyoderma when compared with the normal group (P < 0.01) and dogs suffering from primary seborrhoea (P < 0.05). This is similar to the results of a study of human atopic dermatitis by Cole and Silverberg (1986) who demonstrated increased adherence by S. aureus to keratinocytes from atopic dermatitis patients when compared with adherence to keratinocytes in a variety of non-atopic dermatoses. This increased adherence by pathogenic staphylococci to keratinocytes may in part explain the high incidence of staphylococcal pyoderma seen in both canine and human patients suffering from atopic dermatitis.     

Dose selection of selamectin for efficacy against adult fleas (Ctenocephalides felis felis) on dogs and cats

Selamectin, a novel avermectin, was evaluated in two controlled studies (one in Beagles, one in domestic shorthaired cats) to determine an appropriate topical dose for efficacy against adult Ctenocephalides felis felis (C. felis) fleas on dogs and cats for 1 month. For each study, animals were allocated randomly to four treatments. One treatment consisted of the inert formulation ingredients (vehicle) administered as a negative control, and the other three treatments consisted of a single topical dosage of 3, 6, or 9mgkg(-1) of selamectin. In each study, selamectin was administered as a topical dose applied to the skin in a single spot at the base of the neck in front of the scapulae. Dogs and cats were infested with 100 viable unfed C. felis (50 males and 50 females) on days 4, 11, 18, and 27. Seventy-two hours (+/-2h) after each infestation, on days 7, 14, 21, and 30, a comb count to determine the number of viable fleas present on each animal was performed. Efficacy of selamectin on day 30 was used to select an appropriate dose. For dogs and cats, percentage reductions in geometric mean flea comb counts for the three selamectin treatments ranged from 94. 6 to 100% on days 7, 14, and 21, compared with the negative-control treatment. On day 30, reductions in flea comb counts were 81.5, 94.7, and 90.8% for dogs, and 79.8, 98.0, and 96.2% for cats treated with selamectin at 3, 6, or 9mgkg(-1), respectively. For day 30 flea comb counts for dogs and cats, analysis of variance showed that the three selamectin treatments resulted in significantly (P< or =0.05) lower counts than did the negative-control treatment. For dogs and cats, geometric mean flea counts for selamectin administered at a dosage of 3mgkg(-1) were significantly (P< or =0.05) higher than those for the 6 and 9mgkg(-1) treatment dosages combined. There were no significant differences in flea counts between the 6 and 9mgkg(-1) treatments. This analysis was confirmed by linear-plateau modeling. Thus, the optimal dose of selamectin for efficacy against adult fleas for both dogs and cats, as estimated by the turning point (plateau) in the dose response curve, was 6mgkg(-1).     

蛋鸡坏死性肠炎的诊治

1发病情况 2006年11月21日，河北省辛集市某个体养殖户饲养的2500只海兰褐蛋鸡发病。该批鸡在198日龄时曾用左旋氧氟沙星进行预防性投药．20天后出现采食量下降、腹泻、产量下降、急性死亡等症状，随后用头孢哌酮钠饮水，24小时后腹泻症状明显减轻，随后采食量也逐渐回升。5天后产蛋率也开始回升。     

减少稻桑混作区蚕中毒的几项措施

安徽省泾县地处皖南山区,境内地势多丘陵,土壤肥沃,气候温和,四季分明,全年无霜期239d,宜桑宜稻。泾县栽桑养蚕历史悠久,但粮食生产自古不能自足,近年才基本实现粮食自给。泾县县委、政府十分重视粮食、蚕桑生产的发展,把两大产业作为县域经济的两大主导产业来抓。全县广大农民养蚕、种粮积极性高涨,两大产业齐头并进,蓬勃发展,粮食复种面积和栽桑面积逐年增加,随之而来,稻、桑混作区面积也逐年增加,两者之间矛盾日益显现,突出体现在稻、桑混作区蚕儿农药中毒现象经常发生,造成部分蚕农减产减收。尤其是2005年,泾县双晚水稻稻飞虱大发生,时…