Objective: To study the development of Physocephalus dromedarii(P. dromedarii) in the final host.Methods: For this, 5 adult dromedaries were orally infected with third larval stages of P. dromedarii obtained from natu...Objective: To study the development of Physocephalus dromedarii(P. dromedarii) in the final host.Methods: For this, 5 adult dromedaries were orally infected with third larval stages of P. dromedarii obtained from naturally infected scarab beetles(Scarabaeus cristatus). The camels were necropsied 14, 42, 70, 84 and 280 days after infection and their abomasi were examined for the presence of nematodes.Results: Early 4th stage larva occurred already 2 weeks after infection. They were still in the sheet of the 3rd stage larva. Six weeks after infection, the nematodes became juvenile male and female adults measuring 9 and 10 mm, respectively. Their size doubled at 10 weeks post infection and patency was reached at 12 weeks. P. dromedarii was still present in the camel that was examined 40 weeks after infection.Conclusions: As a result of experimental infection of the natural host, the determined prepatent period of P. dromedarii equalled 12 weeks.展开更多
A long-term blood feeder, like the <i><span>Hyalomma</span></i><span> </span><i><span>dromedarii</span></i><span> tick, requires extended con...A long-term blood feeder, like the <i><span>Hyalomma</span></i><span> </span><i><span>dromedarii</span></i><span> tick, requires extended control over all hemostatic defense mechanisms generated by the host during feeding, including blood coagulation. To overcome this, ticks have evolved numerous molecules that target proteases in the blood coagulation cascade. New insights into the role of clotting factors in the development and progression of cancer have identified anticoagulant treatment as a potential therapeutic approach. In this context, the present work assessed the anticoagulation activities of crude and fractionated salivary gland extract (SGE) prepared from semi-fed </span><i><span>H</span></i><span>. </span><i><span>dromedarii</span></i><span> females. Additionally, the antitumor effects of the potent anti-thrombin fractions were determined against colon cancer (Caco-2) and normal skin (HFB4) cells. Crude SGE significantly prolonged clotting time in prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT) assays and inhibited thrombin in FII-activity assay. Using anion-exchange chromatography, the fractions that strongly inhibited thrombin (3.A4 and 3.A5) were eluted. Both fractions prolonged the aPTT and TT clotting times and reduced the activity of FII significantly. The protein profiles of both fractions indicated the presence of a single polypeptide band of about 99 kDa. Regarding anti-cancer potential of the tested fractions, Caco-2 cells showed reduced viability with obvious morphological changes, induced apoptosis and a reduced level of vascular endothelial </span><span>growth factor (VEGF). G2/M cell cycle arrest was observed only in 3.A5-treated</span><span> cells. No cytotoxic effects were observed in HFB4 cells. These results demonstrated the potential of tick-derived anticoagulants, specifically thrombin inhibitors, as effective tools in colorectal cancer treatment. Further purification of the effector molecule(s) is required to fully characterize their structures and mechanisms of action.</span>展开更多
Hyalomma dromedarii ticks are important disease vectors to camels in the UAE and worldwide. Ticks can be identified using DNA-based techniques. In addition, such techniques could be utilized to study the intraspecific...Hyalomma dromedarii ticks are important disease vectors to camels in the UAE and worldwide. Ticks can be identified using DNA-based techniques. In addition, such techniques could be utilized to study the intraspecific genetic diversity in tick populations. In this study, the genetic diversity of four H. dromedarii populations was investigated using mitochondrial cytochrome c oxidase subunit I (COI) gene and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). The results showed that both of the aforementioned techniques produced similar grouping patterns. Moreover, they revealed that the four tick populations had high levels of genetic similarity. However, one population was slightly different from the three other populations. The current study demonstrated that H. dromedarii ticks in the UAE are very similar at the genetic level and that investigating more locations and screening larger numbers of ticks could reveal larger genetic differences.展开更多
文摘Objective: To study the development of Physocephalus dromedarii(P. dromedarii) in the final host.Methods: For this, 5 adult dromedaries were orally infected with third larval stages of P. dromedarii obtained from naturally infected scarab beetles(Scarabaeus cristatus). The camels were necropsied 14, 42, 70, 84 and 280 days after infection and their abomasi were examined for the presence of nematodes.Results: Early 4th stage larva occurred already 2 weeks after infection. They were still in the sheet of the 3rd stage larva. Six weeks after infection, the nematodes became juvenile male and female adults measuring 9 and 10 mm, respectively. Their size doubled at 10 weeks post infection and patency was reached at 12 weeks. P. dromedarii was still present in the camel that was examined 40 weeks after infection.Conclusions: As a result of experimental infection of the natural host, the determined prepatent period of P. dromedarii equalled 12 weeks.
文摘A long-term blood feeder, like the <i><span>Hyalomma</span></i><span> </span><i><span>dromedarii</span></i><span> tick, requires extended control over all hemostatic defense mechanisms generated by the host during feeding, including blood coagulation. To overcome this, ticks have evolved numerous molecules that target proteases in the blood coagulation cascade. New insights into the role of clotting factors in the development and progression of cancer have identified anticoagulant treatment as a potential therapeutic approach. In this context, the present work assessed the anticoagulation activities of crude and fractionated salivary gland extract (SGE) prepared from semi-fed </span><i><span>H</span></i><span>. </span><i><span>dromedarii</span></i><span> females. Additionally, the antitumor effects of the potent anti-thrombin fractions were determined against colon cancer (Caco-2) and normal skin (HFB4) cells. Crude SGE significantly prolonged clotting time in prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT) assays and inhibited thrombin in FII-activity assay. Using anion-exchange chromatography, the fractions that strongly inhibited thrombin (3.A4 and 3.A5) were eluted. Both fractions prolonged the aPTT and TT clotting times and reduced the activity of FII significantly. The protein profiles of both fractions indicated the presence of a single polypeptide band of about 99 kDa. Regarding anti-cancer potential of the tested fractions, Caco-2 cells showed reduced viability with obvious morphological changes, induced apoptosis and a reduced level of vascular endothelial </span><span>growth factor (VEGF). G2/M cell cycle arrest was observed only in 3.A5-treated</span><span> cells. No cytotoxic effects were observed in HFB4 cells. These results demonstrated the potential of tick-derived anticoagulants, specifically thrombin inhibitors, as effective tools in colorectal cancer treatment. Further purification of the effector molecule(s) is required to fully characterize their structures and mechanisms of action.</span>
文摘Hyalomma dromedarii ticks are important disease vectors to camels in the UAE and worldwide. Ticks can be identified using DNA-based techniques. In addition, such techniques could be utilized to study the intraspecific genetic diversity in tick populations. In this study, the genetic diversity of four H. dromedarii populations was investigated using mitochondrial cytochrome c oxidase subunit I (COI) gene and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). The results showed that both of the aforementioned techniques produced similar grouping patterns. Moreover, they revealed that the four tick populations had high levels of genetic similarity. However, one population was slightly different from the three other populations. The current study demonstrated that H. dromedarii ticks in the UAE are very similar at the genetic level and that investigating more locations and screening larger numbers of ticks could reveal larger genetic differences.
