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Biomedical subjects

N Edington

Publications and source records attributed to N Edington.

At least 73 records · Page 4Linked to original sources
PubMed1982

Ultrastructural changes in the nasal turbinate bones of pigs in early infection with Bordetella bronchiseptica.

The ultrastructural changes in the turbinates of young pigs killed four, seven, 14 and 28 days after intranasal inoculation (dpi) with Bordetella bronchiseptica were restricted to osteoblasts. In a few cells irregularities and evagination of the nuclear membrane were associated with enlargement of the Golgi apparatus at four dpi. By seven dpi many osteoblasts had these changes and also a dilatation of the endoplasmic reticulum while mitochondria retained normal definition: an amorphous degeneration occurred within the enlarged Golgi apparatus. These features had progressed at 14 and 28 dpi to produce shrunken osteoblasts with small, irregular nuclei, a grossly distended endoplasmic reticulum, absent or degenerate Golgi apparatus, but apparently intact mitochondria. At this stage the numbers of osteoid fibres were greatly reduced and macroscopic hypoplasia of the turbinates was observed.

Animals↗
PubMed1980

The detection of the herpesvirus of bovine malignant catarrhal fever in rabbit lymphocytes in vivo and in vitro.

The herpesvirus of bovine malignant catarrhal fever (MCFV, alcelaphine herpes-virus I) causes an acute, fatal lymphoproliferative disorder in rabbits. In dying rabbits, virus antigen and infectivity were associated with medium sized lymphocytes and not with theproliferative lymphoblastoid cells. Virus antigen was found diffusely in the cytoplasm and as diffuse or particulate areas in the nucleus of infected cells. Fresh suspensions of the lymphoid tissues from rabbits killed 1 to 3 days after the onset of pyrexia contained 1 to 4 of both infective and fluorescent antigen positive cells per 10(6) cells. After 2 to 3 days of culture there was a 50- to 1000-fold increase in their concentration when a similar concentration of cells also contained herpesvirus type particles, both in the cytoplasm and the nucleus. About 40- to 100-fold more antigen-positive cells developed in cultures of lymphoid tissues from rabbits killed on the 2nd or 3rd day of pyrexia compared with the cultures from rabbits killed on the first day of pyrexia. Both cytosine arabinoside and 5-iododeoxyuridine inhibited the development of the infected cells upon culture. The findings are discussed in relation to lymphoproliferative disorders caused by other herpesviruses.

Animals↗
PubMed1980

The protection of rabbits against the herpesvirus of malignant catarrhal fever by inactivated vaccines.

Cell-free virulent malignant catarrhal fever virus inactivated by either formalin or acetylethylenimine (AEI) and administered with Freund's complete adjuvant protected rabbits against two consecutive parenteral challenges with cell-free virus. However 'protected' rabbits succumbed within 20 days to later inoculation of infected rabbit lymph node suspensions. Both inactivated vaccines evoked high titres of neutralising and immunofluorescent antibody, but more of the rabbits given the AEI preparation showed pyrexia after the first challenge with cell-free virus. The degree of protection afforded was compared with that induced by inactivated antigens of other herpesviruses which cause lymphoproliferative disorders

Animals↗
PubMed1977

Experimental transplacental transmission of porcine cytomegalovirus.

Six serologically negative sows were infected by intranasal instillation of porcine cytomegalovirus (PCMV) between 31 and 85 days of pregnacy. Four sows showed an afebrile anorexia and lethargy 14-25 days after infection and all 6 developed significant increases in indirect immunofluorescent (IIF) antibody titres within 35 days. Virus was recovered from nasal and/or cervical swabs from 2 sows during life and from lung macrophage cultures after death. At term the sows were killed and their fetuses harvested by caesarean section. The number of mummified and stillborn fetuses increased from 4/63 in 6 previous litters to 18/60 in the 6 present litters. Nine of 43 fetuses born alive were reared in isolators for up to 6 weeks but the majority were killed for examination on the day of birth. Virus was isolated from 16 piglets from 4 of the 6 litters examined; it was isolated most frequently from lungs and liver but also from spleen, kidney, brain and nasal mucosa. Unsuckled day-old pigs had insignificant IIF titres, irrespective of whether they were excreting virus or not. The 5 congenital excretors which were reared all died within 7 days but no death occurred among their 4 litter-mates. Post-natal infection of 2 of these piglets reared in contact with congenitally infected pigs was suggested by the recovery of virus from nasal swabs 17 and 27 days after birth and the subsequent rise in IIF titre to 1/256 by day 42.

Animals↗
PubMed1976

Relationship of porcine cytomegalovirus and B bronchiseptica to atrophic rhinitis in gnotobiotic piglets.

Both porcine cytomegalovirus (PCMV) and Bordetella bronchiseptica produced rhinitis and pneumonia when inoculated intranasally into young gnotobiotic pigs. With PCMV the nasal lesions were confirmed to the lamina propria, while Bordetella produced atrophy of the turbinate bones and hyperplasia and degeneration of the nasal epithelium. Some exacerbation of the lesions was observed in the nasal mucosa of pigs given both agents, but the degree of bone atrophy was not increased.

Animals↗
PubMed1976

Cytomegalovirus excretion in gnotobiotic pigs.

Germ-free piglets were infected intranasally with porcine cytomegalovirus (PCMV) at 1 day (group A) or 3 weeks of age (group B). Viraemia and virus excretion by the nasal, pharyngeal and conjunctival routes was studied up to the time of death or to 12 weeks. Virus was also sought in tissues at death or at slaughter, as well as in a few urine samples. Viraemia was detected in group A between days 5 and 19 after infection and in group B between days 14 and 16 inclusive. The chief route of virus excretion was the nasal mucosa, followed by the pharynx and conjunctiva; the maximal duration of excretion by these routes was 32, 25 and 14 days for pigs of group A and 9, 7 and 4 days for group B. The quantity of virus was also greater in the former group, of which died of generalized PCMV infection. A viruria was demonstrated in 2 animals. Antibody detectable in indirect immunofluorescence (IIF) tests appeared towards the end of the third week, reaching maximal titres at 5 to 7 weeks after infection. The mean peak titre of antibody in group B was lower than in group A. Corticosteroid treatment at days 56--62 after infection resulted in some recrudescence of virus excretion, accompanied in group B by about a twofold increase in IIF antibody. PCMV was isolated in cultures of lung macrophages from 4 of 7 animals killed at about 12 weeks after inoculation.

Animals↗
PubMed1976

The behaviour of porcine cytomegalovirus in commercial pig herds.

A longitudinal, virological and serological study of pigs in two herds with respiratory disease showed that infection by porcine cytomegalovirus (PCMV) was universal in both. Virus excretion usually began when piglets were between 3 and 6 weeks of age and reached a maximum between 5 and 8 weeks; it was usually no longer detectable at 11-12 weeks. Antibody demonstrable in indirect immunofluorescence (IIF) tests was present to moderate or high titre in all piglets at 2-3 weeks. This was presumed to be maternal in origin as it declined in titre between 2-3 and 5-6 weeks. After this fall the majority of piglets showed seroconversion as a result of virus infection. One group of 12 pigs in which infection occurred earlier than usual showed a very poor antibody response, which, nevertheless, persisted through to week 27. The findings are discussed with relation to porcine atrophic rhinitis and cytomegalovirus infection in other species.

Animals↗
PubMed1975

Experimental infection of calves with respiratory syncytial virus.

Three bovine isolates and one human isolate of RS virus were given intranasally to gnotobiotic, colostrum-deprived and conventional calves. All isolates produced a biphasic pyrexia associated with a serous nasal discharge. Virus was recovered from nasal secretions 4-10 days after inoculation from nasal, tracheal and bronchial mucosae and lung of animals killed 7-13 days after inoculation. Infection did not produce any macroscopic lesions, but histologically there was a focal degenerative rhinitis and a catarrhal bronchiolitis with the occasional formation of syncytia in bronchioles and alveoli.

Administration, Intranasal↗