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Biomedical subjects

F O'Connor

Publications and source records attributed to F O'Connor.

At least 55 records · Page 3Linked to original sources
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Correlation of specific antibody titre and avidity with protection in cattle immunized against Fasciola hepatica.

Cattle produce specific serum antibody mainly of the IgG1 isotype in response to infection with the liver fluke, Fasciola hepatica. In these animals a positive correlation between fluke-specific serum IgG1 levels and fluke-burden in non-immunized infected animals was observed. In contrast, immunization of cattle with a combination of the fluke-derived antigens cathepsin L2 (CL2) and fluke haemoglobin (FHb) in Freund's complete/incomplete adjuvant (FCA/FLA) induced a specific antibody response involving IgG2, as well as IgG1. These immunized animals also exhibited very high (72%) levels of protection against a subsequent challenge infection. When the vaccine was administered in FIA alone the specific antibody response, while still involving IgG1 and IgG2, was of lower magnitude (10-fold and 100-fold, respectively) and no significant reduction in fluke burden was observed following challenge. Nevertheless, in these animals, a strong IgG2 response was associated with low fluke burdens. These results provide further evidence of the non-protective nature of specific immune responses in cattle following F. hepatica infection, and demonstrate that vaccination can induce a qualitatively different, and protective, response.

Animals↗
PubMedDate not supplied

Long-term evaluation of venous tissue in the construction of cardiac valves.

We present the evolution of venous tissue, used as a mitral or tricuspid prosthesis or in the reconstruction of the right ventricular outlet tract, for periods of up to 18 months. A histological and hydrodynamic study is made of the valves after sacrificing the animals. The venous tissue showed fibrosis, structural disorganization, elastosis, elastorexis and, above all, intense calcification in heavy deposits. Since the venous tissue evolved toward fibrosis and calcification, its use is considered contraindicated.

Animals↗
PubMedDate not supplied

[Acut aortic insufficiency caused by rupture of a normal valve during labor].

We are presenting a case of a young woman with sudden onset of heart failure and several episodes of syncope, after a prolonged labor. The findings at physical examination suggested the diagnosis of acute aortic insufficiency, that was confirmed by cardiac catheterization. At surgery, the aortic valve showed a round perforation in the non coronary cusp. Pathological examination of the valve showed no significant abnormality. We conclude that the stress of labor was the cause of the rupture of a previously normal aortic valve.

Adult↗
PubMedDate not supplied

Anoxic cardiac arrest: Its effect on myocardial mitochondrial metabolism.

Forty eight healthy dogs are subjects to cardiopulmonary bypass and divide into two groups according to whether the perfusion is performed in normothermia or moderate hypothermia (30 degrees C). The effects on oxidative phosphorylation and mitochondrial respiration, produced by increasing periods of myocardial anoxia from aortic cross clamping, are studied. A clear correlation is found between the disturbances of mitochondrial metabolism and the future cardiac recovery. Hypothermia shows a protective effect on the anoxic myocardium. It is concluded that the period of absolute safety in cardiac anoxia, as far as mitochondrial function is concerned, is 15 minutes in normal thermic perfusion and 90 minutes in moderately hypothermic ones.

Animals↗
PubMedDate not supplied

Traumatic ventricular septal defect: a case of early repair and review of the literature.

We present a case of traumatic ventricular septal defect following a stab wound of the heart. The patient was operated on within the first 24 hours after being injured, because the hemodynamic situation had deteriorated; he is well 31 months postoperatively. From the literature reviewed, it is apparent that most of such lesions should be corrected early, since these patients are exposed to the continued risk of symptomatic cardiac dysfunction, and repair offers an excellent prognosis with minimal morbidity.

Adult↗