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Biomedical subjects

N D Sullivan

Publications and source records attributed to N D Sullivan.

At least 19 recordsLinked to original sources
PubMed1990

Stage-specific immunity to Taenia taeniaeformis infection in mice. A histological study of the course of infection in mice vaccinated with either oncosphere or metacestode antigens.

The course of Taenia taeniaeformis infection in mice previously vaccinated with antigens prepared from either oncosphere (TtO) or metacestode (TtM) was followed by histological examination of livers from mice killed at various times post-infection (p.i.). Distinctly different immune responses occurred in the two groups. Very few cysts were seen at any stage of infection in TtO-vaccinated mice and most of those which were present appeared histologically similar to cysts in control mice. In TtM-vaccinated mice many cysts were present from early in infection but histologically it was apparent that most were dying from 15 days p.i. because the tegument had lost its integrity, and degranulated polymorphonuclear leucocytes were present inside the parasites. These findings support earlier suggestions that stage-specific antigens are expressed in oncospheres and metacestodes. Parasites developing normally were surrounded by a halo of alcian blue staining amorphous acellular material. This material appeared to act as a barrier to attack by host inflammatory cells, and disappearance of this layer signalled death of the parasite. The possibility that the gut acted as a barrier to delay migration of oncospheres to the liver in vaccinated mice was investigated, but no evidence for this could be found.

Animals↗
PubMed1985

An outbreak of lead poisoning in dogs.

An outbreak of lead toxicosis in working dogs on a sheep farm is described. The affected dogs exhibited neurological signs which appeared to be initiated by strenuous physical activity. Radiological examination and estimation of urinary delta aminolevulinic acid (U-ALA) was not found to be useful for clinical diagnosis but blood lead estimation was helpful in detecting and confirming dogs that were exposed to lead. Gross pathological lesions were absent in a lead poisoned dog. However, histopathological lesions were seen in brain and bone. Acid-fast lead inclusion were not detected in liver and kidney epithelial cells but were present in osteoclasts.

Aminolevulinic Acid↗
PubMed1984

Neuropathological lesions in experimental lead toxicosis of dogs.

Light microscopical examinations were carried out on the central and peripheral nervous systems of 9 dogs maintained on a high-fat-low-calcium diet and dosed orally with a mixture of lead chloride, lead bromide and lead sulphate. Microscopic lesions were present in 7 (78 per cent) of the lead-treated dogs. Cerebrocortical lesions comprising spongiosis, vascular hypertrophy and gliosis predominated. These lesions were bilateral, had a predilection for gyri and were located mainly in the parietal and frontal cortex. There were bilaterally symmetrical spongiform changes in the brain stem. The cerebellum had spongiform changes in the roof nuclei and in the lingula there was spongiosis of the Purkinje cell layer and vacuolation of Purkinje cells. Axonal degeneration was evident in a sciatic nerve of one dog. In a second experiment, designed to study the early ultrastructural changes in the brains of dogs with lead intoxication, 2 groups of dogs, one on a commercial balanced diet and the other fed a high-fat-low-calcium diet, were given similar amounts of lead. Cytoplasmic accumulation of lipid was found in the cerebrovascular pericytes of all dogs treated with lead but vascular changes were otherwise not obvious. Quantitative evaluation of numbers of blood vessels by light microscopy revealed an apparent increase in all dogs receiving lead. This increase in vascularity was greatest in the dogs fed the high-fat-low-calcium diet.

Animals↗
PubMed1983

Acid fast inclusions in tissues of dogs dosed with lead.

Liver, kidney and bone from dogs with experimental lead toxicosis were examined to study the frequency of occurrence of acid fast inclusions and the results were correlated with the lead content of these tissues. Light and electron microscopic studies revealed that bone and kidney had characteristic acid fast lead inclusions in 95 and 68 per cent of cases, respectively. Liver, although it had a high lead content, did not often show inclusions. For histopathological diagnosis of lead poisoning in dogs, we suggest that Ziehl-Nielsen stained sections of the epiphyseal area of long bone be examined for the presence of acid fast inclusions in osteoclasts.

Animals↗
PubMed1983

Blood lead and urinary delta aminolevolonic acid (U-ALA) in the diagnosis of lead toxicosis of dogs.

A comparative evaluation of the usefulness of blood lead and urinary delta aminolevolonic acid estimations in the diagnosis of canine lead poisoning was made in 2 dogs which were given increasing quantities of lead by mouth for extended periods. In both lead administered dogs the blood lead levels remained elevated throughout the experimental period of 18 weeks. This contrasted with the results of U-ALA determinations in which elevated levels were detected only infrequently and at erratic intervals lacking relationship to lead exposure.

Aminolevulinic Acid↗
PubMed1982

The effects of age and diet on the absorption of lead from the gastrointestinal tract of dogs.

Two groups of young growing dogs (one group maintained on balanced commercial diet and the other on high-fat-low-calcium diet) and one group of adults dogs on balanced commercial diet were given lead orally at 4 different dose levels. Post-treatment blood lead levels did not reveal any significant difference between the young and adult dogs maintained on balanced commercial diet. However, dogs on the high-fat-low-calcium diet showed marked elevation in blood lead at each of the 4 dose levels used. The results emphasise the importance of dietary factors in absorption of lead from the alimentary tract and suggest that the influence of age on lead uptake from the gut requires further evaluation.

Age Factors↗
PubMed1981

Clinical signs, radiology and tissue lead distribution of dogs administered a mixture of lead chloride, lead bromide and lead sulphate.

Eight-month-old dogs maintained on a high-fat-low-calcium diet were administered a mixture of lead chloride, lead bromide and lead sulphate for prolonged periods at 4 different dose levels. Dogs on high levels of leads showed marked weight loss and gastrointestinal symptoms followed by death. Two dogs on low lead levels developed neurological signs. Radiological investigations showed radiopaque particles in 27 per cent of abdominal radiographs and "lead lines' in the distal radius of 3 dogs. Highest tissue lead levels were found in bones followed by liver and kidney, brain and spinal cord.

Animals↗
PubMed1980

Nurse practitioner and physician's assistant clinics in rural California. Part I: issues.

The primary health care needs of at least 26 rural California communities are being served by nurse practitioners (NP's) or physician's assistants (PA's). All of these have physician supervision and support. NP's and PA's have proved to be acceptable and effective. With 230 rural areas in California identified as having unmet health care needs, this type of service is likely to increase and should be supported.NP/PA clinics serve total populations or concentrate on Indians, Chicanos or the poor. Many barriers have been overcome, especially over the past four years, to allow these clinics to flourish and increase in number. The availability of nurse practitioners and physician's assistants has increased due to support to schools and to school policies. Clinic funding has greatly improved; federal funds for general rural clinics, Indians, migrants, family planning and maternalchild health have been greatly supplemented by California state funds. Beginning in 1978, rural NP and PA services can be reimbursed by Medicare and Medi-Cal (California's Medicaid program).Since 1975 state laws have defined PA and NP roles broadly, and these roles are more precisely defined at the local level. Although nurse practitioners and physician's assistants generally cannot prescribe or dispense drugs (a major problem in many clinics), demonstration legislation allows special pilot projects to do both. As remaining funding and legal problems are corrected, NP's and PA's will serve an even greater role in rural areas.

Ambulatory Care Facilities↗
PubMed1978

Hyperlipaemia in ponies.

The case histories and clinical findings of 15 ponies with hyperlipaemia are presented. The disease was characterised by hyperlipidaemia with inappetance, progressing somnolence, muscle fasciculation, diarrhoea, and ventral oedema as the predominant clinical findings. Post mortem examinations of 12 ponies showed extensive lipidosis and vascular thrombosis with widespread secondary changes. Most cases occurred in late pregnant and early lactating mares in the summer months and it is postulated that the disease was initiated in this group by a falling nutritional plane in the face of high nutrient requirements.

Animals↗
PubMed1978

Histiocytic ulcerative colitis in a Boxer dog.

A 2-year-old male Boxer dog had passed loose faeces mixed with fresh blood and mucus for 8 months. Tenesmus after defaecation was a feature. Colitis was diagnosed from the proctoscopic appearance of the recto-colonic mucosa and confirmed from a biopsy. The disorder proved unresponsive to sulphasalazine therapy, but oral chloramphenicol, betamethasone and prednisolone enemas administered over a 6-week period produced a satisfactory clinical improvement, which persisted for a further 3 weeks without treatment. However, follow-up proctoscopy showed only a marginal improvement in the appearance of the mucosa and appeared to exacerbate further bloody diarrhoea, which persisted. The dog was destroyed and histiocytic ulcerative colitis confirmed at autopsy.

Animals↗