Generalist mammalian predators hunt for prey in different ways than raptors,often relying on ambush attack.Such differences in predator behavior can have profound effects on susceptibility of different species of prey...Generalist mammalian predators hunt for prey in different ways than raptors,often relying on ambush attack.Such differences in predator behavior can have profound effects on susceptibility of different species of prey to predation,but can also modify the behavior of prey.We investigated susceptibility of common birds to predation by domestic cats Felis catus,relying on an extensive data set on prey abundance and prey availability as determined by standardized bird counts.Susceptibility to cat predation for different species of birds was not significantly correlated with susceptibility to predation by sparrowhawk Accipiter nisus,but with susceptibility to goshawk Accipiter gentilis predation. Susceptibility to goshawk predation was independently predicted by susceptibility to cat and sparrowhawk predation.We cross-validated our estimate of susceptibilityto cat predation by showing that the frequency of birds with tail loss increased strongly with sus-ceptibility to cat predation.Male birds were disproportionately preyed upon,especially if havingsong posts low in the vegetation,and if having short flight distances when singing.Colonially breeding species were less susceptible to predation than solitary species.Bird species with high levels of innate immune defense against bacterial infections had high susceptibility to cat predation.These findings suggest that predation by cats has been an important selection pressure affecting anti-predation behavior,sexual display and immune function in common birds.展开更多
AIM:To test the hypothesis that histamine 3 receptor (H3R)activation during Helicobacter infection inhibits gastric acid secretion in vivo and in vitro.METHODS:Helicobacter felis(H.felis)infected and uninfected C57Bl/...AIM:To test the hypothesis that histamine 3 receptor (H3R)activation during Helicobacter infection inhibits gastric acid secretion in vivo and in vitro.METHODS:Helicobacter felis(H.felis)infected and uninfected C57Bl/6 mice were infused with either PBS or the H3 receptor antagonist thioperamide(THIO)for 12 wk.After treatment,mice were analyzed for morphological changes and gastric acid content.Total RNA was prepared from the stomachs of each group and analyzed for changes in somatostatin and gastrin mRNA abundance by real time-polymerase chain reaction(RTPCR).Location of H3 receptors in the stomach was analyzed by co-localization using antibodies specific for the H3 receptor and parietal cell marker H + ,K + -ATPase βsubunit. RESULTS:Inflammation and parietal cell atrophy was observed after 12 wk of H.felis infection.Interestingly, treatment with the H3R antagonist thioperamide(THIO) prior to and during infection prevented H.felis-induced inflammation and atrophy.Compared to the uninfected controls,infected mice also had significantly decreased gastric acid.After eradication of H.felis with THIO treatment,gastric acidity was restored.Compared to the control mice,somatostatin mRNA abundance was decreased while gastrin gene expression was elevated during infection.Despite elevated gastric acid levels, after eradication of H.felis with THIO,somatostatin mRNA was elevated whereas gastrin mRNA was suppressed.Immunofluorescence revealed the presence of H3 receptors on the parietal cells,somatostatin-secreting D-cells as well as the inflammatory cells. CONCLUSION:This study shows that during H.felis infection,gastric acidity is suppressed as a consequence of an inhibitory effect on the parietal cell by H3R activation.The stimulation of gastric mucosal H3Rs increases gastrin expression and release by inhibiting release of somatostatin.展开更多
The objective of the study was to compare the efficacy of one topical insecticide-acaricide (Frontline Tri-Act?) and of one collar (Seresto?) against fleas (Ctenocephalides felis) and ticks (Rhipicephalus sanguineus) ...The objective of the study was to compare the efficacy of one topical insecticide-acaricide (Frontline Tri-Act?) and of one collar (Seresto?) against fleas (Ctenocephalides felis) and ticks (Rhipicephalus sanguineus) on dogs exposed to bi-weekly water showering. Twenty four (24) dogs were enrolled in the study. A first set of 16 dogs were acclimatised to their cages from Day 1 to 7 and a second set of 8 dogs from Day 163 to Day 169. The 24 dogs were randomly allocated to three groups (1 to 3). Dogs assigned to Group 1 were not treated and served as negative controls. Dogs assigned to Group 2 received the Seresto? collar on Day 0 and dogs in Group 3 received Frontline Tri-Act? on Days 170 and 198. The dogs were observed hourly for four hours after treatment administration for possible adverse reactions. Dogs in Groups 1 and 2 underwent water showering on Days 14, 28, 42, 56, 70, 84, 98, 112, 126, 143 and 157. Dogs in all groups underwent water showering on Days 173, 185, 199 and 213. Dogs were infested with approximately 100 (±4) adult, unfed C. felis fleas only on Days 177, 190, 203, and 217, in alternance with infestations with 50 adult unfed R. sanguineus on Days 182, 196, 210, and 224, to assess sustained efficacy. Fleas and ticks were removed and counted on 24 and 48 hours ± 2 hours after each infestation, respectively. Frontline Tri-Act? was >99% effective against C. felis following an initial and a second monthly administration on dogs that were water showered bi-weekly. The Seresto? collar was from 68.3% to 92.9% effective against C. felis Days 178 to 218 after collar administration. Frontline Tri-Act? was effective from 87.8% to 100% against ticks whereas Seresto collar was effective from 82.2% to 94.2% from Day 184 to Day 226.展开更多
The mating behavior of cat flea, Ctenocephalides felis (Bouche) was studied on an artificial feeding device. Male and female can mate repeatedly with same partner or different ones. In the situation of male: femal...The mating behavior of cat flea, Ctenocephalides felis (Bouche) was studied on an artificial feeding device. Male and female can mate repeatedly with same partner or different ones. In the situation of male: female ratio of 1:5, each mating lasted an average of 6.6 min, with a mean interval between matings at 2.5 min., compared to 11.1 min and 12.1 min respectively in a cell with 5 males and 1 female. As many as 48 mating events were observed for one male during an 8 h period. One female mated 27 times in 7 h with 5 males in the same cell. Newly emerged males and females can not mate before blood meal and about 24 h blood feeding is required for successful mating. Newly emerged males can not mate with fed females (fed for 48 h), but fed males can mate with newly emerged females who are feeding the blood. Significantly more male contacts and male male mating attempts were observed after the paper treated with female extract was introduced into the cell. The paper contacts and mating attempts were 16.75-32.25 times and 15.75-31.38 times, respectively, on average during a period of 20 min when different doses (FE) of extract were provided.展开更多
目的对中哈边境阿拉山口口岸入境货车携带的活猫体表采集的寄生物进行鉴定与病原体检测。方法在入境的活猫体表采集到蚤类,经形态学和分子鉴定后,采用PCR方法检测鼠疫耶尔森菌、巴尔通体、立克次体、贝纳氏柯克次体、沃尔巴克氏体,并对...目的对中哈边境阿拉山口口岸入境货车携带的活猫体表采集的寄生物进行鉴定与病原体检测。方法在入境的活猫体表采集到蚤类,经形态学和分子鉴定后,采用PCR方法检测鼠疫耶尔森菌、巴尔通体、立克次体、贝纳氏柯克次体、沃尔巴克氏体,并对阳性产物进行序列测定和系统进化分析。结果在1只入境活猫体表采集到147匹蚤(28组),形态学与分子鉴定均为猫栉首蚤指名亚种。5种病原体检测只有沃尔巴克氏体核酸阳性。16S r DNA基因扩增结果显示与分离自阿拉山口的客蚤属(Xenopsylla sp)的内共生菌同源性达99.9%,wsp基因扩增结果显示与江苏杂拟谷盗(Tribolium confusum)的内共生菌同源性达到100%。系统进化分析显示猫栉首蚤指名亚种携带的沃尔巴克氏体内共生菌与国际上报道的处于不同分支。结论中哈边境阿拉山口口岸从入境的猫栉首蚤指名亚种检出沃尔巴克氏体内共生菌。展开更多
为建立一种快速、准确检测猫等孢球虫的方法,本研究采用GenBank登录的猫等孢球虫18s r RNA基因序列(L76471.1)保守区设计并合成1对特异引物,从经显微镜检测为猫等孢球虫阳性的粪便样品中选取一份提取猫等孢球虫DNA,以其为模板经PCR扩增...为建立一种快速、准确检测猫等孢球虫的方法,本研究采用GenBank登录的猫等孢球虫18s r RNA基因序列(L76471.1)保守区设计并合成1对特异引物,从经显微镜检测为猫等孢球虫阳性的粪便样品中选取一份提取猫等孢球虫DNA,以其为模板经PCR扩增猫等孢球虫18s r RNA基因片段,构建重组质粒标准品p UCm-T-IF1并经PCR及测序鉴定正确后作为质粒标准品。通过优化反应条件,建立了猫等孢球虫的荧光定量PCR检测方法。特异性试验结果显示,该方法可以特异性的检测猫等孢球虫DNA,对猫贾第虫、猫滴虫、猫细小病毒、猫冠状病毒DNA/cDNA的检测结果均为阴性;对重组质粒标准品的检测限可达6.26×10^(2)拷贝/μL。批内和批间重复性试验的变异系数分别是0.61%~2.06%和0.32%~0.50%。表明本研究建立的方法特异性强、敏感性高、重复性好。利用该方法对23份临床疑似猫等孢球虫感染的样品进行检测,荧光定量PCR的检出率为78.26%(18/23),明显高于漂浮法检测的阳性率43.48%(10/23),并且经漂浮法检测为阳性的样品采用该方法检测均为阳性。结果表明,本研究建立的荧光定量PCR方法能够更准确的检测猫等孢球虫的感染,为开展猫等孢球虫病和流行病学调查提供更准确的检测手段。展开更多
文摘Generalist mammalian predators hunt for prey in different ways than raptors,often relying on ambush attack.Such differences in predator behavior can have profound effects on susceptibility of different species of prey to predation,but can also modify the behavior of prey.We investigated susceptibility of common birds to predation by domestic cats Felis catus,relying on an extensive data set on prey abundance and prey availability as determined by standardized bird counts.Susceptibility to cat predation for different species of birds was not significantly correlated with susceptibility to predation by sparrowhawk Accipiter nisus,but with susceptibility to goshawk Accipiter gentilis predation. Susceptibility to goshawk predation was independently predicted by susceptibility to cat and sparrowhawk predation.We cross-validated our estimate of susceptibilityto cat predation by showing that the frequency of birds with tail loss increased strongly with sus-ceptibility to cat predation.Male birds were disproportionately preyed upon,especially if havingsong posts low in the vegetation,and if having short flight distances when singing.Colonially breeding species were less susceptible to predation than solitary species.Bird species with high levels of innate immune defense against bacterial infections had high susceptibility to cat predation.These findings suggest that predation by cats has been an important selection pressure affecting anti-predation behavior,sexual display and immune function in common birds.
基金Supported in part by Public Health Service Grants R37-DK45729(JLM)Michigan Gastrointestinal Peptide Research Center Pilot Feasibility Grant P30-DK34933(YZ)National Health and Medical Research Council of Australia Grant 350234(AS)
文摘AIM:To test the hypothesis that histamine 3 receptor (H3R)activation during Helicobacter infection inhibits gastric acid secretion in vivo and in vitro.METHODS:Helicobacter felis(H.felis)infected and uninfected C57Bl/6 mice were infused with either PBS or the H3 receptor antagonist thioperamide(THIO)for 12 wk.After treatment,mice were analyzed for morphological changes and gastric acid content.Total RNA was prepared from the stomachs of each group and analyzed for changes in somatostatin and gastrin mRNA abundance by real time-polymerase chain reaction(RTPCR).Location of H3 receptors in the stomach was analyzed by co-localization using antibodies specific for the H3 receptor and parietal cell marker H + ,K + -ATPase βsubunit. RESULTS:Inflammation and parietal cell atrophy was observed after 12 wk of H.felis infection.Interestingly, treatment with the H3R antagonist thioperamide(THIO) prior to and during infection prevented H.felis-induced inflammation and atrophy.Compared to the uninfected controls,infected mice also had significantly decreased gastric acid.After eradication of H.felis with THIO treatment,gastric acidity was restored.Compared to the control mice,somatostatin mRNA abundance was decreased while gastrin gene expression was elevated during infection.Despite elevated gastric acid levels, after eradication of H.felis with THIO,somatostatin mRNA was elevated whereas gastrin mRNA was suppressed.Immunofluorescence revealed the presence of H3 receptors on the parietal cells,somatostatin-secreting D-cells as well as the inflammatory cells. CONCLUSION:This study shows that during H.felis infection,gastric acidity is suppressed as a consequence of an inhibitory effect on the parietal cell by H3R activation.The stimulation of gastric mucosal H3Rs increases gastrin expression and release by inhibiting release of somatostatin.
文摘The objective of the study was to compare the efficacy of one topical insecticide-acaricide (Frontline Tri-Act?) and of one collar (Seresto?) against fleas (Ctenocephalides felis) and ticks (Rhipicephalus sanguineus) on dogs exposed to bi-weekly water showering. Twenty four (24) dogs were enrolled in the study. A first set of 16 dogs were acclimatised to their cages from Day 1 to 7 and a second set of 8 dogs from Day 163 to Day 169. The 24 dogs were randomly allocated to three groups (1 to 3). Dogs assigned to Group 1 were not treated and served as negative controls. Dogs assigned to Group 2 received the Seresto? collar on Day 0 and dogs in Group 3 received Frontline Tri-Act? on Days 170 and 198. The dogs were observed hourly for four hours after treatment administration for possible adverse reactions. Dogs in Groups 1 and 2 underwent water showering on Days 14, 28, 42, 56, 70, 84, 98, 112, 126, 143 and 157. Dogs in all groups underwent water showering on Days 173, 185, 199 and 213. Dogs were infested with approximately 100 (±4) adult, unfed C. felis fleas only on Days 177, 190, 203, and 217, in alternance with infestations with 50 adult unfed R. sanguineus on Days 182, 196, 210, and 224, to assess sustained efficacy. Fleas and ticks were removed and counted on 24 and 48 hours ± 2 hours after each infestation, respectively. Frontline Tri-Act? was >99% effective against C. felis following an initial and a second monthly administration on dogs that were water showered bi-weekly. The Seresto? collar was from 68.3% to 92.9% effective against C. felis Days 178 to 218 after collar administration. Frontline Tri-Act? was effective from 87.8% to 100% against ticks whereas Seresto collar was effective from 82.2% to 94.2% from Day 184 to Day 226.
文摘The mating behavior of cat flea, Ctenocephalides felis (Bouche) was studied on an artificial feeding device. Male and female can mate repeatedly with same partner or different ones. In the situation of male: female ratio of 1:5, each mating lasted an average of 6.6 min, with a mean interval between matings at 2.5 min., compared to 11.1 min and 12.1 min respectively in a cell with 5 males and 1 female. As many as 48 mating events were observed for one male during an 8 h period. One female mated 27 times in 7 h with 5 males in the same cell. Newly emerged males and females can not mate before blood meal and about 24 h blood feeding is required for successful mating. Newly emerged males can not mate with fed females (fed for 48 h), but fed males can mate with newly emerged females who are feeding the blood. Significantly more male contacts and male male mating attempts were observed after the paper treated with female extract was introduced into the cell. The paper contacts and mating attempts were 16.75-32.25 times and 15.75-31.38 times, respectively, on average during a period of 20 min when different doses (FE) of extract were provided.
文摘目的对中哈边境阿拉山口口岸入境货车携带的活猫体表采集的寄生物进行鉴定与病原体检测。方法在入境的活猫体表采集到蚤类,经形态学和分子鉴定后,采用PCR方法检测鼠疫耶尔森菌、巴尔通体、立克次体、贝纳氏柯克次体、沃尔巴克氏体,并对阳性产物进行序列测定和系统进化分析。结果在1只入境活猫体表采集到147匹蚤(28组),形态学与分子鉴定均为猫栉首蚤指名亚种。5种病原体检测只有沃尔巴克氏体核酸阳性。16S r DNA基因扩增结果显示与分离自阿拉山口的客蚤属(Xenopsylla sp)的内共生菌同源性达99.9%,wsp基因扩增结果显示与江苏杂拟谷盗(Tribolium confusum)的内共生菌同源性达到100%。系统进化分析显示猫栉首蚤指名亚种携带的沃尔巴克氏体内共生菌与国际上报道的处于不同分支。结论中哈边境阿拉山口口岸从入境的猫栉首蚤指名亚种检出沃尔巴克氏体内共生菌。
文摘为建立一种快速、准确检测猫等孢球虫的方法,本研究采用GenBank登录的猫等孢球虫18s r RNA基因序列(L76471.1)保守区设计并合成1对特异引物,从经显微镜检测为猫等孢球虫阳性的粪便样品中选取一份提取猫等孢球虫DNA,以其为模板经PCR扩增猫等孢球虫18s r RNA基因片段,构建重组质粒标准品p UCm-T-IF1并经PCR及测序鉴定正确后作为质粒标准品。通过优化反应条件,建立了猫等孢球虫的荧光定量PCR检测方法。特异性试验结果显示,该方法可以特异性的检测猫等孢球虫DNA,对猫贾第虫、猫滴虫、猫细小病毒、猫冠状病毒DNA/cDNA的检测结果均为阴性;对重组质粒标准品的检测限可达6.26×10^(2)拷贝/μL。批内和批间重复性试验的变异系数分别是0.61%~2.06%和0.32%~0.50%。表明本研究建立的方法特异性强、敏感性高、重复性好。利用该方法对23份临床疑似猫等孢球虫感染的样品进行检测,荧光定量PCR的检出率为78.26%(18/23),明显高于漂浮法检测的阳性率43.48%(10/23),并且经漂浮法检测为阳性的样品采用该方法检测均为阳性。结果表明,本研究建立的荧光定量PCR方法能够更准确的检测猫等孢球虫的感染,为开展猫等孢球虫病和流行病学调查提供更准确的检测手段。
