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Biomedical subjects

D J Burden

Publications and source records attributed to D J Burden.

54 records · Page 3Linked to original sources
PubMed1987

Measurement of class specific antibody against cryptosporidium in serum and faeces from experimentally infected calves.

Anti-cryptosporidium antibody levels were measured in serum and faeces of experimentally infected calves. In serum, IgG was detectable six days after infection and remained elevated throughout infection. IgA and IgM in serum showed little change. IgG, IgA and IgM levels all rose in the faeces five or six days after infection and reached a peak between days 8 and 14 after infection and then declined.

Animals↗
PubMed1984

Experimental concurrent infection of cattle with Ostertagia ostertagi and Salmonella dublin.

Six seven-month-old Friesian steers were given 8.1 X 10(9) Salmonella dublin orally. Four had been infected with third stage larvae of Ostertagia ostertagi on four occasions over the previous three months. All became pyrexic and excreted S dublin in the faeces for eight to 15 days. Intravenous injection of 8.7 X 10(8) S dublin six weeks later produced similarly mild effects in parasitised and control animals alike. Two parasitised animals stopped excreting S dublin after three and five weeks respectively; the other four were still excreting regularly when killed eight weeks after intravenous infection. S dublin was recovered from the carcases of all six. O ostertagi, unlike Fasciola hepatica, did not increase susceptibility to S dublin or predispose to prolonged infection.

Animals↗
PubMed1983

Fasciola hepatica: migration of newly excysted juveniles in resistant rats.

Using transmission and scanning electron microscopy, the early migration of juvenile Fasciola hepatica was examined in naive and resistant rats. In naive rats, the migration of flukes to the peritoneal cavity was uneventful. In resistant rats, flukes were rapidly coated with antibody whilst still in the gut lumen and a proportion of the flukes were unable to penetrate the intestinal wall. Those that did penetrate were unharmed as they crossed the gut wall, but on entering the peritoneal cavity they were coated with antibody and host cells including eosinophils, neutrophils, macrophages, and mast cells. Eosinophils were seen degranulating onto the fluke surface, and this appeared to result in the erosion of the tegumental syncytium.

Animals↗
PubMed1983

Fasciola hepatica: development of the tegument of normal and gamma-irradiated flukes during infection in rats and mice.

Rats and mice were infected with either normal metacercariae or metacercariae gamma-irradiated at 3 krad. or 4 krad. Flukes were recovered at various times after infection and their teguments examined using a transmission electron microscope. In normal flukes, the secretory granules T0, T1 and T2 were all seen during tegumental development. The teguments of flukes from mice developed faster than the corresponding teguments in rats. T0 granules were present from day 0 to day 10 post-infection (p.i.) in mouse flukes and from day 0 to day 14 p.i. in rat flukes. T1 granules first appeared in mouse flukes by day 4 p.i. but not until day 8 p.i. in rat flukes. T2 granules were seen in mouse flukes 2 days p.i. but not before 6 days p.i. in rat flukes. gamma-Irradiation at 4 krad prevented normal tegumental development in flukes from both rats and mice. T0 granules were present at all times in flukes from either host. T1 granules were produced in mouse flukes but their appearance was delayed until day 6 p.i. No significant production of T2 granules occurred in flukes from either host. Parasite survival was also affected by gamma-irradiation and none of the flukes reached maturity. Flukes from rats died between 10 and 21 days p.i. and flukes from mice died between 14 and 28 days p.i. gamma-Irradiation of metacercariae at 3 krad. had an extremely variable effect on subsequent tegumental development in both rats and mice. Some flukes developed normally, some showed development associated with gamma-irradiation at 4 krad, whilst some showed intermediate development.

Animals↗
PubMed1982

Fasciola hepatica: attempts to immunise rats and mice with metabolic and somatic antigens derived from juvenile flukes.

Attempts were made to vaccinate rats and mice against Fasciola hepatica using either somatic or metabolic antigens derived from juvenile flukes between 10 and 16 days old. None of the regimes tried induced a good resistance to subsequent infection, though metabolic antigens derived from 13-14-day-old flukes when injected subcutaneously into rats with adjuvant did produce some protection to challenge.

Animals↗
PubMed1981

Fasciola hepatica: a technique for the study of gut penetration by juvenile flukes.

A method using light and electron microscopes is described which is suitable for the examination of gut penetration by juvenile Fasciola hepatica. It involved the ligation of small sections of the small intestine of rats and the introduction of artificially excysted flukes into these gut loops. By restricting the area of infection in this way it was possible to either recover flukes from the gut lumen or to prepare ultrathin sections for electron microscopy of flukes penetrating the gut wall. In addition, flukes were recovered from the body cavity at various times after preparation of loops in resistant and naive rats. It was found that more flukes reached the body cavity in naive rats than in resistant rats, demonstrating a resistance to infection in the gut loops of sensitized rats.

Animals↗
PubMed1979

The development and survival of Trichuris suis ova on pasture plots in the south of England.

Pasture plots in the south of England were contaminated each month throughout 1975 with pig faeces containing Trichuris suis ova. At regular intervals thereafter, soil samples were taken, the T suis ova extracted and their state of development noted. Depending on the time of year that the plots were contaminated, ova required between 62 and 90 weeks to complete their development to the infective stage. Little or no development occurred during winter. Once the infective stage was reached, the ova survived for at least two years. Samples taken from the plots at various depths demonstrated that T suis ova did not rapidly leach through the soil but were still available to grazing pigs up to two and a half years later. The early developmental stages of ova appeared to be more susceptible to desiccation than those that had developed to the blastula stage or beyond.

Animals↗
PubMed1978

Concurrent daily infection of calves with Fasciola hepatica and Ostertagia ostertagi.

Three groups of calves were infected daily with either 1500 Ostertagia ostertagi larvae, 20 Fasciola hepatica metacercariae, or 1500 O ostertagi plus 20 F hepatica metacercariae. Weekly measurements were taken of calf weight, faecal egg output, plasma concentrations of albumin, plasma activities of sorbitol dehydrogenase, gamma glutamyl transpeptidase and pepsinogen and standard haematological indices. Calves were killed either 10 or 21 weeks after daily infections began. F hepatica infection had little influence on the size and structure of the O ostertagi worm population or vice versa. Mean worm burdens found at 20 weeks in those animals infected with both F hepatica and O ostertagi were 293 flukes and 20,641 nematodes. While this level of infection is similar to that seen in the disease complex in the field, there was no evidence of clinical disease or any difference in weight gain between the groups in this experiment. Factors other than additive worm burdens are obviously important for the expression of disease under field conditions.

Abomasum↗
PubMedDate not supplied

Ankylosis: an orthodontic problem with a restorative solution.

This case illustrates a restorative approach using adhesive techniques to overcome the aesthetic and functional problems associated with infraclusion of a mandibular canine tooth resulting from ankylosis. In this case a diagnosis of ankylosis was confirmed after 3 months of fixed appliance orthodontic therapy failed to extrude the tooth.

Adult↗