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Biomedical subjects

M M Sewell

Publications and source records attributed to M M Sewell.

At least 37 records · Page 2Linked to original sources
PubMed1984

Metazoan parasites of dogs in Sabah, Malaysia.

The parasites which occurred most frequently in 175 owned or stray dogs in Sabah were Ancylostoma spp. present in 68% of the animals. Dirofilaria immitis occurred in 70% of the adult dogs but neither D. immitis nor Spirocerca lupi were present in puppies under four months of age. The latter attained a prevalence of 30% in the adults. In contrast Toxocara canis occurred in 81% of the puppies but infrequently in older dogs. Dipylidium caninum was moderately prevalent (15 to 25%) in dogs of all ages. Ticks were the most common arthropod parasite being present on 26% of the dogs and were mainly Rhipicephalus sanguineus. Demodectic and sarcoptic mange were confirmed and fleas and lice were also recovered.

Animals↗
PubMed1984

Variation in 'target' antigens between appropriate and inappropriate hosts of Taenia saginata metacestodes.

The antibody response of the appropriate hosts (cattle) to Taenia saginata larvae was compared with that of an inappropriate host (Balb/c mice) using gel electrophoresis followed by immunoelectrotransfer blot techniques (Western blotting). Three groups of cattle were included, those known to be resistant to challenge infection because of repeated oral challenge with T. saginata eggs over a 1-year period, a previously infected but known susceptible group and a group of uninfected controls. Serum from the mice and the two groups of infected cattle contained antibodies recognizing different 'target' antigens, some of which may be related to host resistance. The potential value of the technique of Western blotting in dissecting the humoral response of a particular host species to parasitic infection and in the identification of those antigens suitable for the production of effective vaccines is discussed.

Animals↗
PubMed1984

Absorption of cysticerci in cattle after treatment of taenia saginata cysticercosis with praziquantel.

Two groups of calves aged 10 to 15 weeks were orally infected with either 6000 or 30,000 Taenia saginata eggs. Three to four months later they were treated with praziquantel, three doses of 50 mg kg-1 on three consecutive days. All the cysticerci were killed by the drug and most were absorbed by between six and nine months after treatment. From then on there was little further absorption and residual calcified cysts were still found in the carcases up to 24 months after drug treatment. These residual calcified cysts were particularly common in the heart muscles and would probably have been detected at meat inspection.

Animals↗
PubMed1983

The specificity of somatic and metabolic Taenia taeniaeformis preparations in murine metacestode infections.

Excretory-secretory and somatic preparations of Taenia taeniaeformis contained shared immunologically-active components although immunoelectrophoresis indicated that the major antigen present in the excretory-secretory preparation was only a minor component of the somatic preparation. Both antigens gave similar immunoelectrophoretic reactions with sera from mice infected with either T. taeniaeformis or Taenia crassiceps, but there was evidence from the results using the ELISA technique that the excretory-secretory components showed more species specificity than those of somatic origin.

Animals↗
PubMed1983

Duration of immunity and absorption of cysticerci in calves after treatment of Taenia saginata cysticercosis with praziquantel.

Calves were first infected with 5000 Taenia saginata eggs at six to 10 weeks old and treated with praziquantel 12 weeks later. Complete immunity against challenge lasted for at least 12 weeks following anthelmintic treatment. Six months after drug treatment over 90 per cent of the cysticerci had been completely absorbed but some were still detectable especially in the heart. An increase was observed in the ELISA values of sera from infected calves following treatment with praziquantel, but no such rise was detected in sera from resistant calves after challenge infection.

Age Factors↗
PubMed1981

Varying infectivity of Taenia taeniaeformis for rats and mice.

Strains of Taenia taeniaeformis were shown to possess markedly differing infectivities for Sprague-Dawley rats and CFI mice. Strains from Scotland, Belgium and Iraq were more infective for mice than rats while this situation was reversed with a Malaysian strain. There were also differences in their ability to infect hosts of different ages within the range 3-12 weeks of age.

Animals↗
PubMed1981

In vitro hatching and activation of Taenia taeniaeformis oncospheres.

Previously described techniques for hatching eggs of Taenia taeniaeformis were found to give inconsistent and generally ineffective results, even the degree of disaggregation of the embryophore varying with the strain of parasite. Furthermore, the hatched and activated oncospheres did not survive in the hatching fluid. Following a series of studies on the composition of the hatching fluids, a more reliable procedure was developed. Pretreatment with hypochlorite, at 0.67% w/w available chlorine, caused disaggregation of the embryophoral blocks of virtually all the eggs. When this was followed by exposure to a solution containing 10 mg.ml-1 trypsin, 10% ox bile and 10% heat-inactivated foetal calf serum in modified RPMI with HEPES buffer and L-glutamine, about 50% of the viable oncospheres were activated and escaped from the oncospheral membrane. Most of the activated oncospheres survived in this hatching fluid for at least three hours.

Animals↗
PubMed1981

Inoculation of calves and adult cattle with oncospheres of Taenia saginata and their resistance to challenge infection.

Following intramuscular inoculation of Taenia saginata eggs hatched in vitro, 1-month-old calves were capable of developing a complete immunity to the establishment of a living infection by oral challenge. Cysticerci developed at the injection sites and produced an effective immunity whether the hatched oncospheres were activated in vitro or not. A few living cysticerci found at sites other than the inoculation sites were derived from the inoculation dose and parasite migration from the inoculation sites was also observed in control calves which had not been orally challenged. Such migration was much less frequent in adult cattle. Adult cattle which had been orally infected many times were resistant to infection by intramuscular inoculation. Disseminated infections developed in young calves infected by the intravenous and intraperitoneal routes with hatched eggs. The ELISA test was found to be more sensitive at detecting serological antibodies in infected calves than the IHA test.

Animals↗
PubMed1981

A comparison of the enzyme linked immunosorbent assay and the indirect haemagglutination technique applied to sera from cattle experimentally infected with Taenia saginata (Goeze, 1782).

The serological response of 6 calves to experimental oral infection with between 60,000 and 100,000 Taenia saginata eggs at 3-12 months of age was monitored by the enzyme-linked immunosorbent assay (ELISA) and the tanned cell indirect haemagglutination technique (IDH). A serum antibody response was detected by both techniques by 2-3 weeks post infection, rising to a plateau about 4-6 weeks post infection. The serum antibody levels began to decline by about 30 weeks post infection. Two uninfected control cattle gave negative reactions. In addition, the serological response of 5 calves which had received a dose of 10,000 T. saginata eggs at 2-3 days of age and then weekly serial doses of 500 eggs for 12 months thereafter, was compared with a similar group of 5 calves, which had received the single infection of 10,000 eggs at 2-3 days of age only. Calves in both groups developed an antibody response detectable by the ELISA technique whereas those in a group of 5 control calves did not show such a response. When studied individually however there was marked variation in the serum antibody levels of these young cattle, as although some calves gave a relatively strong serological response, others hardly varied from the controls.

Animals↗
PubMed1980

Parasitic gastro-enteritis in calves on the Jos plateau, Nigeria.

An experiment in which groups of calves were repeatedly treated with thiabendazole and compared with similar untreated groups suggested that parasitic gastroenteritis is not a problem in calves kept under traditional management during the wet season on the Jos plateau in northern Nigeria. On the other hand, as the dry season advanced, the effect of earlier treatment during the wet season showed in better weight gains, higher serum albumin concentrations and higher packed cell volumes compared to the controls. The epidemiological significance of this is discussed in relation to the nutritional stresses of the dry season.

Animals↗
PubMed1980

Resistance to Fasciola hepatica in rats and rabbits following implantation of adult flukes contained in diffusion chambers.

Resistance to Fasciola hepatica could be elicited in rats by implanting mature flukes subcutaneously or intraperitoneally in diffusion chambers. A similar resistance occurred even when the implants were removed two weeks before challenge. This excluded the possibility that the continuing presence of the sensitising flukes was necessary for the maintenance of resistance and also showed that the resistance could be elicited by only two weeks exposure to diffusible immunogens emanating from the flukes.

Animals↗