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Biomedical subjects

A Baskerville

Publications and source records attributed to A Baskerville.

At least 109 records · Page 6Linked to original sources

Quantitative studies on the development of the bronchi and bronchial glands of the pig from birth to maturity.

Cross-sectional areas of bronchi and bronchial glands of pigs aged from 1 day to 10 months were measured using image analysis. Growth of the bronchial glands was slow for the first month of life, reached a maximum between 1 and 3 months, and slowed again after 5 months. Mucous gland sizes fell into two groups, one included the apical, cardiac and accessory lobes, the other the diaphragmatic lobes. From birth to maturity the percentage increase in mucous gland area of all lobes was very similar. For the anterior lobes, mucous glands and bronchial lumina grew in direct proportion to each other. Up to 1 month of age the bronchial lumina of the diaphragmatic lobes grew but the glands did not. Later, glands and lumina grew in direct proportion. From birth to maturity the percentage increase in bronchial cross-sectional area was similar for all lobes.

Age Factors↗

The pathology of untreated and antibiotic-treated experimental tularaemia in monkeys.

Grivet monkeys were infected intranasally with the virulent Schu-S4 strain of F. tularensis. One group of animals remained untreated and two other groups received a 7-day course of kanamycin therapy starting on either the third or fourth day after infection. Untreated monkeys developed pyrexia and mucopurulent oculonasal discharge and died 5--7 days after infection. All had pyogranulomatous lesions in the liver, spleen, respiratory tract and lymph nodes. Electron microscopy of liver and spleen showed phagocytosis of F. tularensis organisms by macrophages and polymorphonuclear leucocytes, but many bacteria survived phagocytosis and were released on destruction of the cells. Kanamycin therapy enabled most monkeys to survive the disease, but it did not prevent the development of persistent lesions in all animals. Caseous nodules were larger and more widespread in the organs of monkeys in which treatment was delayed until the fourth day of infection.

Animals↗

Changes in whole blood and serum components of grivet monkeys with experimental respiratory Francisella tularensis infection.

Grivet monkeys infected with virulent Francisella tularensis Strain Schu S4 showed significant early changes in serum levels of trace metals, triglycerides and activities of alkaline phosphatase, lactate dehydrogenase and alpha-hydroxybutyrate dehydrogenase. Free amino acid levels decreased slightly and there was a marked increase in the phenylalanine: tyrosine ratio. Serum lysozyme activity and seromucoid levels also increased. Kanamycin therapy produced remission of overt signs but the changes in blood constituents were less readily affected. Immunization with the live vaccine strain of F. tularensis induced transient responses similar to those resulting from Schut S4 infection. Immunized monkeys subsequently challenged with the virulent Schu S4 strain showed no clinical signs or marked changes in blood constituents.

Animals↗

Effects of swab materials and transport media on Aujeszky's disease virus.

The effect of swab materials on the recovery of Aujeszky's disease virus from various transport media held at 4 degrees C was investigated over a five day period. No significant loss in infectivity was found in control preparations, approximately 50 per cent of infectivity was recovered from fluids containing applicator wire and approximately 10 per cent from fluids containing polyester fibre or cotton wool. Virus recovery from fluids containing wooden applicator sticks ranged from no virus recovery in protein free media to from 1 to 10 per cent in protein containing media. Freezing followed by thawing was the most effective of the physical methods used for eluting virus from swab materials.

Culture Techniques↗

Histopathological effects of methotrexate on mouse liver.

Mice were injected with up to 9 doses of methotrexate and killed at intervals after treatment. Liver changes were assessed histopathologically and by image analysis, and included vacuolation and ballooning degeneration of centrilobular liver cells. There was considerable irregularity in nuclear size in methotrexate-treated mice, in which hepatic nuclei were significantly larger than those of control animals. Fatty change was not induced in the liver by these doses of methotrexate, and there was no cellular infiltration or fibrosis.

Animals↗

Experimental infection of monkeys with Herpesvirus suis (Aujeszky's-disease virus).

Monkeys were infected intranasally with Herpesvirus suis. After an incubation period of 7 to 13 days the animals became acutely ill and rapidly died. Clinical signs included salivation, incoordination, ataxia and epileptiform convulsions, but not pruritus. Histopathological changes were confined to the central nervous system, and consisted of destruction of neurones with the formation of intranuclear inclusion bodies, gliosis and perivascular cuffing. Virus was isolated from the brain and spinal cord in the later stages of the illness but neutralising antibodies were not detected in serum. The distribution of lesions indicated direct spread of virus from the inoculation site along cranial nerves to the brain.

Animals↗

Intestinal lesions induced experimentally by methotrexate.

Mice were given up to 9 doses of methotrexate intermittently over a 3-week period. Inhibition of mitosis occurred in the duodenum, jejunum and ileum after the first injection, and after 2 doses the crypt epithelium showed megalocytosis and occasional abnormal mitotic figures. Further treatment produced degeneration of the epithelium of the villi, which became irregular and atrophic, and the amount of crypt tissue was greatly reduced. Focal ulceration and haemorrhage occurred in some animals. Changes in the caecum and colon developed later and were much milder. After withdrawal of methotrexate the intestinal mucosa rapidly recovered and was normal 1 week later.

Animals↗

The development and persistence of bronchialgland hypertrophy and goblet-cell hyperplasia in the pig after injection of isoprenaline.

Pigs were injected i.m. with isoprenaline sulphate on 6 consecutive days. In the bronchial mucosa of animals killed 24 hr after the sixth injection there was a significant increase in the ratio of submucosal gland thickness to bronchial-wall thickness, indicating glandular hypertrophy. The hypertrophy was due to an increase in size of mucous cells, which were filled with secretion. There was also a much higher proportion of acid glycoprotein in the mucous acini of IPN-treated pigs compared with those of controls. This acid glycoprotein was predominantly sialomucin, but a small quantity of sulphomucin, not present in the normal animal, was observed. IPN also caused a significant increase in the number of goblet cells in the bronchial epithelium, but there was no change in their glycoprotein type, most containing exclusively sialomucin. IPN produced a significant increase in the weight of the salivary and adrenal glands, and of the heart, in which the right and left ventricles were hypertrophied equally. Examination of pigs killed up to 3 mth after IPN showed that the submucosal gland hypertrophy persisted for about 1 mth and the goblet cell hyperplasia persisted for 2 mth.

Animals↗

Histological and ultrastructural observations on the development of the lung of the fetal pig.

Lungs of fetal pigs having gestational ages ranging from 80 to 115 days were examined histologically and by electron microscopy. At 80 days bronchial epithelium was ciliated but bronchiolar cells were not and bronchial mucosal glands were absent. Peripheral regions consisted predominantly of mesenchymal tissue with glandular alveoli. 92 days marked the transition from the immature to the more mature lung type. Bronchial glands appeared and began to grow from the epithelium into the lamina propria, bronchiolar epithelial cells acquired cilia, and alveoli were becoming irregular in shape and had thinner interalveolar septa. Close contact between capillaries and alveolar epithelium established the blood-air barrier at many points. Differentiation of alveolar epithelium into types I and II pneumonocytes occurred at this stage and lamellated osmiophilic inclusion bodies were present in type II cells for the first time. The number of lamellated bodies increased progressively to term at 115 days.

Animals↗

The pathogenesis and pathology of experimental Quaranfil virus infection.

Mice were infected intranasally with Quaranfil arbovirus, and killed at intervals from 1 day to 2 months later. The infection produced clinical signs of neurological disturbance and a highly mortality. The virus could be isolated from the lungs on Days 1-9 and from the brain on Days 1-11 of the infection. Meningoencephalitis developed by Day 5 in the olfactory lobes and spread progressively caudally, involving all regions of the brain by Day 7. The prinicipal features of the inflammatory process were perivascular cuffing, necrosis of neurones, and, in the later stages, spongiform degeneration and marked astrocytic and microglial activity. In the lungs after a short and mild exudative phase interstitial pneumonia developed. This was characterized by proliferation of connective tissue cells in interalveolar septa and later by fibrosis.

Animals↗

Pathogenesis and pathology of respiratory tularaemia in the rabbit.

The development of pathological lesions in the organs of rabbits was examined at intervals from 1 h to 4 days after aerosol infection with Francisella tularensis. The earliest change, accumulation of polymorphonuclear leucocytes (PMN) in ulmonary alveolar ducts, occurred at 19 h. From the 2nd day multiple foci of necrosis and PMN infiltration were present in large airways and alveoli throughout the lungs and progressively increased in size. Pulmonary arteritis was a prominent feature of the infection. Areas of necrosis were present in the nasal mucosa, pharynz and trachea, and pyogranolomatous lesions consistently developed in the liver, spleen, and lymph nodes.

Animals↗

Effects of isoprenaline and pilocarpine on salivary glands as assessed by gravimetric and image analysis techniques.

Pigs were given 6 daily injections of isoprenaline or pilocarpine. At necropsy the parotid, submaxillary and sublingual salivary glands were removed and weighed. Histological sections were prepared from several regions of each gland and the cross-sectional area of their acini was measured in treated and control animals by means of a Quantimet Image Analysis System. Both isoprenaline and pilocarpine produced a significant increase in the weight of the parotid and submaxillary glands, which was accompanied by an increase in acinar area. There was no change in the weight of the sublingual gland with either drug, but isoprenaline did induce an increase in the area of sublingual acini. A comparison is made of the changes in weight and structure of the salivary glands as shown by these methods.

Animals↗

Histochemical identification of glycoproteins in pig bronchial epithelium: (a) normal and (b) hypertrophied from enzootic pneumonia.

The glycoproteins in the normal pig bronchial gland are identified by the combined Alcian Blue (AB)-periodic acid Schiff (PAS) technique, with the use of sialidase digestion and AB staining either at pH 2-6 or at pH 1-0. In enzootic pneumonia (produced experimentally by infection with Mycoplasma hyorhinis) the bronchial gland hypertrophies, mucous and serous cells both increase, in number and size; hence the total glycoprotein content of the gland increases. The distribution of glycoproteins in the hypertrophied gland differs from that in the normal. Quantitative analysis of the mucous cells shows that in the hypertrophied gland the acid glycoprotein is increased relative to the neutral. There is also a relative change in the amounts of sialidase-sensitive sialomucin and sulphomucin; both are significantly increased at the expense of the sialidase-resistant sialomucin. Qualitative analysis of the serous cells shows that in the normal gland most of the glycoprotein is neutral and that the small amount of acid glycoprotein is sialidase-resistant sialomucin. In the hypertrophied gland there is relatively more acid glycoprotein which is either sialidase-resistant sialomucin or sulphomucin; in addition, in pigs with enzootic pneumonia there is an increase in the height of the bronchial epithelium and a depletion in both goblet cell number and glycoprotein content, which latter has more neutral glycoprotein and less acid glycoprotein.

Animals↗