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Biomedical subjects

E M Allan

Publications and source records attributed to E M Allan.

31 records · Page 2Linked to original sources
PubMed1980

Clinical and epidemiological features of 15 incidents of severe infectious bovine rhinotracheitis.

Fifteen incidents of infectious bovine rhinotracheitis (IBR) were studied in herds distributed widely throughout northern Britain. Fattening beef animals (10 outbreaks), dairy cattle (four outbreaks) and suckler beef cows (one outbreak) were affected and all bar one incident occurred in housed cattle during the winter. The first signs of illness noticed were a reduced appetite, dullness, coughing and oculonasal discharge. In 13 of the incidents they were observed in cattle purchased from a market within the previous four weeks. In every outbreak, affected animals developed a serous nasal discharge which became purulent in severe cases. In the early stages the nasal mucosa was congested but later yellow-brown diphtheritic plaques developed. In such animals halitosis was always detected. Soft coughing was frequently heard but pneumonia was rarely confirmed ante mortem. Conjunctivitis and ocular discharge were a major finding in 13 incidents and, in severely affected cases, conjunctival oedema was seen. The drooling of saliva was noticed in 14 incidents but congestion of the oral mucous membranes was the only abnormality found on examination of the oral cavity. Diarrhoea was a consistent feature in one outbreak. As a result of contracting this disease beef cattle failed to put on weight for a period of one to eight weeks and the milk yield of lactating dairy cattle decreased markedly. The morbidity rate was high, being more than 90 per cent in 10 incidents. The mortality rate varied considerably but 7 to 8 per cent of the animals died, or were culled, in three outbreaks. The clinical signs were most severe on intensive units with a high turnover of cattle.

Animals↗
PubMed1980

The pathological features of severe cases of infectious bovine rhinotracheitis.

In recent outbreaks of infectious bovine rhinotracheitis (IBR) in Britain a proportion of the animals affected developed a severe clinical disease characterised, at necropsy, by widespread damage to the respiratory tract. They had necrotising rhinitis, pharyngitis, laryngotracheobronchitis with extensive pseudomembrane formation and severe pneumonia with or without interstitial emphysema. Renal infarction was seen in approximatley half of the cases. The central nervous system was not affected in any of the 25 animals with severe IBR examined in this study. Tissues from the respiratory tract of 14 animals were examined for the presence of bovine herpesvirus 1 and the virus was isolated from the nasal passages of 11 and the lungs of four. Mycoplasma bovis was frequently isolated in large numbers from both the upper and lower respiratory tract.

Animals↗
PubMed1980

Scanning electron microscopy of the tracheal epithelium of calves inoculated with bovine herpesvirus 1.

Tracheal epithelium was examined by light, scanning electron and transmission electron microscopy at four, five and seven days after calves were infected intranasally with bovine herpesvirus. Similar areas were examined from uninoculated calves. Tracheal epithelial lesions were found in all inoculated calves and their degree of severity did not vary with the interval between inoculation and examination. Extensive loss of cilia leaving areas of tracheal epithelium covered by microvilli was the main feature.

Animals↗
PubMed1979

Immunoglobulin containing cells in the bronchopulmonary system of non-pneumonic and pneumonic calves.

In an examination of the immunoglobulin containing cells in the respiratory mucosa of three-month-old non-pneumonic calves, IgA was found to be the predominant plasma cell type. In calves with cuffing pneumonia there was a marked increase in the plasma cell population in the bronchial wall and IgG1 cells became the major cell type. Similarly in calves with an exudative type of pneumonia IgG1 plasma cells were the significant cell type in the respiratory mucosa but the total number of plasma cells was similar to that found in the non-pneumonic animals. The immunohistochemical results suggest that IgA and, to a lesser extent, IgM are both transported across the mucous membrane via bronchial epithelial secretory cells and submucosal glands.

Animals↗
PubMed1978

Some characteristics of a natural infection by parainfluenza-3 virus in a group of calves.

Parainfluenza-3 (Pi3) virus infection in a group of 25 calves is described. The virus was isolated from the lungs of four calve at days 6, 7, 13 and 55 after they were housed together at birth. Intracytoplasmic inclusion bodies were seen by light microscopy in bronchial and bronchiolar epithelial cells of two of these calves. Virus infected cells were detected by electron microscopy in three of the four calves. Haemagglutination inhibition antibodies to Pi3 virus were found in the sera of the calves. Despite the virus being present in the group from one week, a significant increase in antibody titre was found in only two animals although all the calves were in contact with each other during the study period. The pulmonary lesions in the four infected calves consisted of a bronchitis and bronchiolitis with infiltration of the walls and lumena of these structures by neutrophils and an adjacent neutrophil infiltration of alveoli some of which were collapsed.

Animals↗
PubMed1978

The ultrastructure of the brush cell in bovine lung.

A cell type with properties similar to those of the brush cell was recognised in the bronchial epithelium of calves. It occurred in small numbers and was not found in airways distal to the small bronchi. The ultrastructural features are described, emphasising the two constant characteristics (i) a dense population of thick apical microvilli and (ii) cytoplasmic filament bundles which extent into the microvilli.

Animals↗
PubMed1975

Mycoplasmas and cuffing pneumonia in a group of calves.

The mycoplasmas found in the lungs of 20 calves, housed together for six months, and the related pulmonary pathology are reported. Twelve calves had cuffing pneumonia and in this group there was a significantly higher isolation frequency of Mycoplasma dispar and Ureaplasma spp compared with the non-pneumonic group. Mycoplasma bovirhinis and Acholeplasma laidlawii were isolated from the lungs of calves in both groups. Mycoplasma arginini was not recovered from the lungs of any calf. The significance of the peribronchiolar lymphocytic accumulation in the lungs of the non-pneumonic animals and their differentiation from peribronchiolar lymphocytic cuffs is discussed.

Acholeplasma laidlawii↗
PubMedDate not supplied

A histochemical study of mucosubstances in the bovine respiratory tract with special reference to cuffing pneumonia.

The mucosubstances of the bronchial epithelial goblet cells in non-pneumonic calves were almost exclusively sulphomucin; neutral mucin, sialomucin and sulphomucin were produced by the submucosal glands. Calves with lesions of cuffing pneumonia from which M. dispar was frequently cultured had increased numbers of epithelial goblet cells extending into the peripheral airways as far as the bronchioles. These pneumonic animals had epithelial goblet cells, some of which contained sialomucin, while in the gland a switch from neutral to acid mucosubstance in the form of increased sulphomucins and sialomucins was detected.

Animals↗