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During the past two years at the University of Modena, 72 sheep underwent cardiopulmonary bypass (CPB) for various open-heart surgical procedures. An effective protocol for anaesthesia and CPB was developed in these animals. Routine barbiturate induction and maintenance anaesthesia with isofluorane and a pressure-regulated ventilator have minimized anaesthetic problems. The type of priming fluid used was the major factor in overcoming the problems associated with haemodilution effects, clotting insufficiency and postperfusion lung syndrome. Pump flows of 60ml.kg -1 bodyweight.min-1 seem to give adequate circulatory support during heart-lung bypass. A technical report and the pharmacological support protocols used successfully in 66 of the 72 animals during a two-year period are presented.

Twenty large white pigs underwent normothermic right ventricular bypass, pulmonary artery valve excision and right ventricular outflow tract (RVOT) reconstruction using a synthetic material (Mitrathane). The animals were divided in two groups (ten for each group) for the RVOT reconstruction model: Group I with a composite monocusp patch (with a new design geometrically related to pulmonary artery circumference) and Group II without a valve mechanism. Four early postoperative deaths occurred in Group I (unrelated to monocusp patch function) and seven in Group II (due to acute right ventricular failure). Follow up of the six animals of Group I was 600-630 (average 617.5) days and of the three Group II animals was 95-110 (average 101.6) days. In Group I haemodynamic studies showed no significant difference from preoperative values at 5 months while at 20 months there was a moderate valve insufficiency in all animals. In Group II severe right ventricular insufficiency was present in all animals and spontaneous death occurred after about 3 months. In Group I angiographic studies disclosed no evidence of graft calcification or stenosis while in Group II there was a moderate pulmonary trunk dilatation. Post mortem examination showed no signs of degeneration in any graft. Microscopic studies of both groups revealed an acellular layer of fibrin on the external surface and fibrous deposit on the inner part of the suture with the right ventricle. In Group I there were leukocyte and histocyte infiltration of the grafts. In these experiments our synthetic monocusp model showed good function and durability in comparison to a RVOT reconstruction without a valve mechanism.

Ten Pericarbon valve bioprostheses were examined after being implanted in tricuspid position in two different groups of animals: group I sheep with increased immunoglobulins, plasma levels, and eosinophilis count of more than 10%, due to parasitic infection, and group II sheep without any parasitic infection, i.e. with normal blood data. The explanted valve follow up was between 60-95 hours in both groups. Microscopic observation of group I valves revealed a massive blood cell (lymphocytes, eosinophilis and large mononuclear cells) infiltration especially around the natural pericardial blood vessels in the region of flexion and attachment. The epipericardial surface was covered by fibrin sheath, and immunofluorescence studies showed a strongly positive reaction for immunoglobulins (IgG and IgE) on leaflet surfaces and lamellar stratification into the fibrosa. Microcalcifications were detected around pericardial blood vessels in the same zones where infiltrated blood cells were found. In group II valves cell infiltration was absent with no signs of calcification and immunofluorescence was negative. Our data suggest that immunoglobulins adherence followed by blood cell infiltration may be one of the early causes of tissue leaflet degeneration and there is a parallel trend between plasma immunoglobulin levels and the early tissue alteration. Our data show that the experimental model for testing bioprostheses in sheep is influenced by the pre-immunological status and it is important to control it before surgery.

The Massa Lombarda program (MLP) is the first step of a European multi-center program, promoted and coordinated from Bologna University's Academic Spin off Health Research and Development, which attempts to manage advanced sanitary research in general population. The -instant individual definition (IID) study is the first phase of the program concerning the study of risk factors (RF) and early diagnosis of coronary heart disease (CHD), through a new diagnostic technology called myocardial perfusion scoring system (MPS). The study consists of a longitudinal observational epidemiological investigation of adult population (above 25 years of age) resident in Massa Lombarda (Ravenna), with the survey of social and biological parameters. The elderly part of the population (1000 subjects above 75 years) was submitted to a more complex analysis, as part of the study on health status in European aging populations, aimed at revealing the determinants influencing the healthy aging, and at identifying their impact on mortality, cardiovascular and respiratory morbidity, disability and decline of quality of life. Laboratory analyses were aimed at identifying the following factors: (i) Genetic markers related to pro-and anti-inflammatory cytokine- codifying genes. (ii) Oxidative stress-involved molecules, and inflammation-involved genes, and more in general genes involved in the brittleness (ApoE). (iii) Appraising the degree of interaction with non-genetic factors, like measurable immunological markers in the peripheral blood, markers of reactions to oxidative stress, evaluation of metabolic parameters. Moreover, old population is expected to answer the questionnaires for evaluation of the dietary habits, physical activity, self-sufficiency, cognitive ability, motor coordination, perceived stress and social relationships.