Search PubMed⌕ Search

Biomedical subjects

D J Alexander

Publications and source records attributed to D J Alexander.

At least 145 records · Page 8Linked to original sources
PubMed1983

The characterization of monoclonal antibodies to Newcastle disease virus.

Monoclonal antibodies to the haemagglutinin-neuraminidase (HN), fusion (F), polymerase and nucleocapsid polypeptides of Newcastle disease virus were prepared. Two epitopes were recognized on the HN polypeptide: one was associated with inhibition of haemagglutination and poor neutralization and the other with good neutralization and no inhibition of haemagglutination. The most effective neutralizing antibody was that produced against the F polypeptide. The poorer neutralization associated with the antibody against the HN epitope was augmented by antiglobulin or complement. The monoclonal antibodies that inhibited haemagglutination also inhibited neuraminidase activity when fetuin but not neuraminyl lactose was the substrate.

Antibodies, Monoclonal↗
PubMed1982

Identification of paramyxoviruses isolated from birds dying in quarantine in Great Britain during 1980 to 1981.

During 1980 to 1981 a total of 61 paramyxoviruses were isolated from imported captive birds dying during the quarantine period required under the Importation of Captive Birds Order 1976. These viruses were identified as avian paramyxovirus serotype PMV-1, 13 isolates (eight Newcastle disease viruses of high virulence, five of low virulence); PMV-2, 38 isolates; PMV-3, nine isolates and one isolate provisionally typed as PMV-7.

Animals↗
PubMed1982

Isolation of influenza A viruses from birds in Great Britain during 1980 and 1981.

During 1980 and 1981 influenza A viruses of subtypes H3N2, H3N8, H4N1, H4N6, H6N2, H6N8, H7N7, H11N8 and H11N9 were isolated from birds in Great Britain, usually as a result of investigations of disease or death. However, all viruses were shown to be of low virulence for chickens in pathogenicity index tests. There was one occurrence of influenza virus infection of turkeys (H6N8) but viruses were frequently obtained from domestic ducks. Other viruses were isolated from exotic birds in zoos or bird collections.

Animals↗
PubMed1981

The structural polypeptides of avian paramyxoviruses.

The structural polypeptides of twenty-three avian paramyxoviruses from five serotypes were examined by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate under reducing and non-reducing conditions. All virus polypeptide profiles consisted of 7--10 polypeptides of which two were glycosylated. Some variation was seen in the profiles of viruses from the same serotype, but groups formed on the basis of their serological relationships in haemagglutination inhibition tests were identical to those formed on the basis of similarities in their polypeptide profiles.

Antigens, Viral↗
PubMed1980

A two year survey on the control of the importation of captive birds into Great Britain.

The operation of the Importation of Captive Birds Order 1976 is described. In the first 24 months that the order was effective, a total of 183,189 birds were landed. Of these 5829 (3.18 per cent) were dead on arrival, 8643 (4.71 per cent) died in quarantine and 474 batches of carcases were submitted for post mortem examination. Chlamydia infections were diagnosed in birds from 14 quarantine/isolation lots and salmonellae were isolated from 23 lots. Thirty-six haemagglutinating agents were isolated from 17 quarantine/isolation lots. These were identified as eight influenza A viruses with Hav 7 Neq 2 subtypes (associated with two importations); 14 influenza A viruses with Hav 4 Nav 1 subtypes (six importations); four yucaipa-like paramyxoviruses (three importations); four 449-like paramyxoviruses (two importations); one unspecified paramyxovirus; five Newcastle disease viruses (NDV) (two importations). Four of the NDV isolates, associated with one importation, were shown to be velogenic viruses by intravenous pathogenicity index tests in six-week-old chickens.

Animals↗
PubMed1980

Avian infectious bronchitis virus structural polypeptides: effect of different conditions of disruption and comparison of different strains and isolates.

Variations in the conditions used for disruption of purified virus involving differences in heat treatment and reducing agent concentration produced little affect on the polypeptide profiles of the Massachusetts 41 (M 41) strain of avian infectious bronchitis virus obtained by polyacrylamide gel electrophoresis. Comparisons of the structural polypeptides of 12 IBV isolates, consiting of M 41, six serologically related viruses and representatives of five other serotypes, showed that the viruses could be placed in three groups on the molecular weights of the major glycopolypeptides. These were 31,000 and 86,000 for M 41, the six related viruses and the serologically distinct SE 17; 27,000 and 89,000 for Iowa 97 and Holte and 27,000 and 91,000 for Connecticut and T strain.

Centrifugation, Density Gradient↗
PubMed1980

The polypeptide composition of isolated surface projections of avian infectious bronchitis virus.

Disruption of avian infectious bronchitis virus (IBV) particles with 4% Triton X-100 and 1.0 M-KCl and centrifugation through a sucrose gradient containing 0.1% Triton X-100 and 1.0 M-KCl enabled separation of the petal-shaped surface projections. By negative-contrast electron microscopy the separated projections appeared mainly as rosettes containing 3 to 12 projections radiating from a central core, although single projections and rosettes containing up to 16 projections were seen. SDS-PAGE of these preparations revealed two polypeptides of 86,000 and 66,000 mol. wt. The larger polypeptide was glycosylated.

Coronaviridae↗
PubMed1980

Isolation and properties of viruses from poultry in Hong Kong which represent a new (sixth) distinct group of avian paramyxoviruses.

Eight viruses isolated in Hong Kong were shown to be serologically related. One was obtained from the tracheal swab of a chicken and four were from cloacal swabs of ducks sampled at a poultry dressing plant. Three isolations were made from samples taken at a duck farm: two from pond water and one from faeces. Representatives of these isolates were shown to be paramyxoviruses but were serologically distinct from other avian and mammalian paramyxoviruses by haemagglutination inhibition and neuraminidase inhibition tests. Slight variations were seen in the properties of three isolates examined in detail. All three were apathogenic for chickens. The structural polypeptides of one isolate, PMV-6/duck/Hong Kong/199/77, were examined by SDS-polyacrylamide gel electrophoresis. Seven polypeptides were detected, with mol. wt. 180000, 76000, 60000, 55000, 51000, 48000 and 40000. The isolates represent a sixth serologically distinct avian paramyxovirus group.

Animals↗
PubMed1980

A simple method of oral endotracheal intubation in rabbits (Oryctolagus cuniculus).

A rabbit to be intubated was anesthetized with a volatile inhalation anesthetic using a face mask and placed in an outstretched prone position. The head was tilted back to the vertical position and a lubricated, straight, endotracheal tube inserted through the mouth into the trachea during inspiration. This procedure was used successfully and repeatedly in 118 rabbits.

Anesthesia, Inhalation↗
PubMed1979

Properties of a newly isolated, serologically distinct avian paramyxovirus.

The morphological, bio-physical and growth properties of the isolate duck/Hong Kong/D3/75 (D3/75) were consistent with this virus being a member of the paramyxovirus group. Using haemagglutination inhibition and neuraminidase inhibition tests no serological relationships between D3/75 and other paramyxoviruses could be demonstrated. The structural polypeptides of D3/75 were also typical of paramyxoviruses, consisting of 6--7 polypeptides ranging in molecular weight from 46,000--200,000 under reduced conditions. Two polypeptides were glycosylated.

Animals↗
PubMed1979

Antigenic and structural relationships between avian paramyxoviruses isolated from ducks in Hong Kong and Mississippi, U.S.A.

Representative isolates of the paramyxoviruses duck/Hong Kong/75 and duck/Mississippi/75 were shown to be serologically closely related by haemagglutination and neuraminidase inhibition tests. The structural polypeptides of these viruses were also shown to be similar. For each of the isolates tested, polyacrylamide gel electrophoresis in the presence of SDS revealed a similar polypeptide pattern consisting, under reducing conditions, of seven polypeptides with apparent mol. wt. ranging from 46000 to 190000. Each virus had two glycosylated polypeptides with apparent mol. wt. of 56000 and 71000 to 72000 under reducing conditions and 62000 to 63000 and 135000 to 142000 under non-reducing conditions.

Animals↗