فهرست مطالب شهاب الدین سهرابی

Establishment of experimental cystic echinococcosis (CE) in laboratory mice is required for the study of CE. Experimental CE may be established in primary or secondary forms; however, the primary form is more reliable for the study of CE.

The aim of the study was to assess the possibility of establishment of primary CE in Balb/c mice via the oral administration of Echinococcus granulosus s.l. eggs.

E. granulosus s.s. eggs were obtained from the gravid segments of the adult worms collected from an experimentally infected dog. Thirty-four female Balb/c mice were allocated into 4 groups and were orally infected with E. granulosus s.s. eggs as follows: 1) the mice with normal immunity, a single dose of 1000 eggs, 2) the mice with normal immunity, 3 doses of 500 eggs, 3) immunosuppressed mice, a single dose of 1000 eggs, and 4) immunosuppressed mice, 3 doses of 500 eggs. After 6.5 months, all the mice were opened and their internal organs were examined for the presence of CE cysts. The livers of infected mice were also examined for the presence of E. granulosus s.l. compartments by the PCR method.

There was no developed or developing CE cyst in the abdominal cavities or on the internal organs of all the mice in four groups. In addition, in the molecular study, all the examined liver samples were negative for the parasite material.

The results of the present study revealed that Balb/c mice are not a suitable host for establishment of primary CE following the oral administration of E. granulosus s.s. eggs.

Bovine theileriosis is important disease in tropical and subtropical areas with great economic losses in livestock husbandry in Iran. The aim of study was to assess the prevalence of Theileria annulata infection in cattle and Hyalomma species of Kermanshah Province, Iran. A number of 138 blood samples were randomly taken from examined cattle. The genomic DNA was extracted and PCR was performed to specifically amplify a 721-bp-long fragment of the 30 Kilo Dalton major merozoite surface antigen (30 KDa msa) of T. annulata. The amplified products were digested with TaqI, Rasl, and AluI restriction enzymes. Overall prevalence was 9.44% (13/138) with lymphadnopathy (1.17%) and pale mucosal membrane (1.9%) in Holstein cattle aged <1 year and more than 5 years-old, respectively. Five species of genus Hyalomma (18.8%, 141/750) including Hyalomma anatolicum anatolicum (30.4%), H. anatolicum excavatum (31.2%), H. marginatum (36.8%), H. asiaticum asiaticum (0.7%), and H. detritum (0.7%) were identified. The tick indices for each Hyalomma species were ranged from 0.01 to 0.36. PCR findings indicated that 3 out of 138 blood samples (2.17%) and 19 out of 141 Hyalomma ticks (4.13%) were infected with T. annulata. Amplified PCR products from blood samples generated similar RFLP patterns, but different RFLP pattern for T. annulata from H. anatolicum anatolicum (9.21%) and H. anatolicum excavatum (4.2%). The RFLP patterns of the amplified fragment of the 30 KDa msa of T. annulata indicated the circulation of four different T. annulata isolates of H. anatolicum anatolicum and H. anatolicum excavatum in the region.

In this paper, the effect of the injector geometry has been investigated on ‎characteristics of the internal nozzle flow and the cavitation phenomenon. To ‎this end, the cavitational flow inside a multi-hole diesel injector was simulated ‎using the computational fluid dynamics. The flow inside the nozzle was ‎considered transient and biphasic (liquid phase and vapor phase) and was ‎simulated using the Eulerian two-fluid model, which is a non-homogeneous ‎model. In this model, governing equations were solved for each phase ‎separately. The interaction between phases was modeled using relevant ‎interfacial exchange terms. To investigate the effect of the nozzle geometry on ‎the cavitational flow, the number of injector holes was varied from 2 to 8. ‎Results showed that by increasing the number of nozzle holes, the structure ‎and the intensity of the vortex flow in the nozzle sac and holes are extremely ‎varied. From the nozzle flow characteristics point of view, an increase in the ‎number of nozzle holes, resulted in a reduction in the injection velocity and the ‎mass flow rate and an increase in the cavitation intensity. Furthermore, the ‎discharge coefficient and the effective area of the nozzle fall with increasing the ‎number of nozzle holes. The simulation method was validated by comparing ‎numerical results with experimental data and a good agreement was achieved.‎

Ticks(Acari: Ixodidae) have been recognized as important ectoparasites of livestock worldwide, including in Iran. From the point of the pathogen agent's transmission,detection of the distribution of hard ticks in different parts of the country could be useful This study reports the frequency and diversity of ticks in all age groups of both sexes in the natural habitat of domestic ruminants in Kermanshah province, Iran.A total of 600 ruminants (203 cattle,215 sheep,and 182 goats) from 150 flocks (90 in the east and 60 in the west part of the region) of 31 villages (15 in the east and 16 in the western part of the region) were randomly selected and examined from May to September 2012. Of all examined animals,24.63% cattle, 25.12% sheep,and 25.27% goats were infested with a total number of 1031 unfed ixodid ticks.The highest numbers of the hard ticks were collected from 3-4 year-old female cattle and 1-2 year-old female sheep and goats in the region.There was significant difference between age groups and sex of infested animals and prevalence of ixodid ticks.The ixodid tick indices were 4.6,7.9, and 7.1 for cattle, sheep,and goats, respectively.Geographical distribution of ixodid ticks infestations in different parts of Kermanshah province revealed that 12 cattle flocks (8%) and 12 goat flocks (8%) in the Miandarband region of eastern Kermanshah and 20 sheep flocks (13.33%) of Meidandam in western Kermanshah had the highest prevalence.Prevalence of ixodid tick infestation was statistically different between both parts of the region.The highest tick aggregation was found for inner thighs in cattle (46%) and ears in sheep (54%) and goats (43%). There was significant difference between predilection body sites of collected hard ticks from infested animals.Of all examined ticks (1031),three genera including Hyalomma, Rhipicephalus, and Boophilus with eight, nine, and seven species in cattle, sheep, and goats were respectively identified.The predominant infesting ticks were R. sanguinus (26.2% in cattle) and R.turanicus (53.1% in sheep and 40.55% in goats) from the western part of Kermanshah province, which was significantly different. The results of the current study showed that ixodid ticks infestation was widespread and prevalent in ruminants of the region.