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Biomedical subjects

R Ferrari

Publications and source records attributed to R Ferrari.

At least 433 records · Page 24Linked to original sources
PubMed1984

The effect of maternally derived antibodies on the response of calves to vaccination against foot and mouth disease.

Studies were carried out in South America to assess the effect of maternally derived antibody (MDA) on the responsiveness of calves to FMD vaccination. It was found that calves with MDA did not merely fail to respond to vaccination, but that their serum titres were depressed. This depression was proportional to the level of pre-existing MDA at the time of vaccination and following primary vaccination it persisted for a least 60 days. High MDA titres interfered with both primary and secondary responses. Animals with relatively low MDA titres were able to respond to vaccination, or at least to be sensitized so that on revaccination they showed a satisfactory response. The half-life of MDA was shown to be approximately 22 days, suggesting that under field conditions significant MDA titres are likely to persist for 4-5 months. A trial carried out in Brazil in which the primary course of two inoculations, 4 weeks apart, was initiated when the calves were 5-6 months of age, resulted in the reduction of FMD in the calf population from 11% to 0.9% over a 12-month period. The use of vaccination programmes of this type to lessen the incidence of FMD in young bovines is discussed.

Animals↗
PubMed1984

Reversible and irreversible ischaemic damage: importance of energy metabolism.

In this study the effects of different degrees and duration of coronary flow reduction on pressure development of the isolated and perfused rabbit hearts has been studied. Three different degrees of ischaemia lasting for 30, 60 and 90 minutes have been investigated, after which the effects of post-ischaemic reperfusion have been followed. The effects of substituting FFA for glucose as myocardial substrate has also been investigated. Reperfusion resulted in a recovery of mechanical function or in a further worsening of mechanical function, depending upon the degree, duration of flow reduction and substrate employed. To establish the causes of reperfusion damage, in a separate series of experiments the effects of reperfusion after 90 minutes of severe ischaemia on lactate, CPK and Mg++ release, tissue and mitochondrial calcium content tissue ATP and CP concentration and mitochondrial function have been determined. The ultrastructural damage of the myocardial cell have also been established. The results obtained suggest that mitochondria play an important role in reperfusion damage.

Adenosine Triphosphate↗
PubMed1983

[Current trends in malignant gastric lymphoma].

Gastric lymphomata represent an important chapter of the oncologic pathology, for both their low incidence and the difficulties for surgeons in the preoperative recognition of such disease. The authors, after a careful study about this subject, report two cases they had the opportunity to observe.

Adenocarcinoma↗
PubMed1983

[Alkaline reflux after gastric resection using the Billroth II method].

Among the more indicative complications encountered in gastrectomized patients, particularly in those cases where the Billroth II technique is used, bile and/or pancreatic reflux is undoubtedly one of the most important manifestations. The abolition of the "sphincteric" function of the pylorus creates a pathophysiological condition of the above-mentioned type when the surgery is not combined with specific antireflux techniques or when particular situations obtain which make alkaline reflux inevitable. These pathophysiological disorders lead to a "chronic gastritis of the stump", which often exhibits differing symptomatic pictures. There are patients in whom there is no correspondence between the anatomo-pathological and symptomatic pictures and who do not suffer at all, phereas there are others (5-35%) who complain of severe symptoms such as epigastric pain aggravated by ingestion of food, reduction in weight, nausea, bile vomiting and often haemorrhagic stillicide with consequent sideropaenic hypochromic anaemia. Taking the above-mentioned considerations as their starting point, the authors set out to investigate these complications more thoroughly in the pathology of gastrectomized patients by means of the long-term follow-up of such patients coming to them for observation after having been subjected to surgical therapy in the form of Billroth II gastric resection (gastro-enterostomy according to Balfour-Kroenlein, or according to Hofmeister-Fininsterer). The study, which is currently still in progress, involves a thorough clinical examination of the symptoms complained of as well as radiological, gastroscopic, histological and haematochemical investigations. The authors report on their preliminary results.

Acid-Base Equilibrium↗
PubMed1983

[Biliary ileus (description of 2 clinical cases)].

Biliary ileus is a rare complication of the biliary pathology, appearing through obstructive pictures of patients in advanced age. After a careful study about this subject, the authors report two cases they had he opportunity to observe.

Aged↗
PubMed1983

Vitamin E and the heart: possible role as antioxidant.

When cardiac muscle becomes hypoxic the cells become oedematous and the fine ultrastructure is altered. Developed tension declines and resting tension increases. The cellular stores of ATP and CP are depleted and the mitochondria exhibit an altered respiration, characterized by a reduced state III respiration and a lowered respiratory control index. Reoxygenation results in a further increase of the hypoxic damage. Using these changes in function as indices of the severity of the damage caused by hypoxia and reoxygenation, we have investigated whether the administration of alfa-tocopherol provides protection. Adult male New Zealand white rabbits were used. The hearts were isolated, Langendorff perfused and then made hypoxic. Alfa-tocopherol acetate was infused directly into the aorta inflow cannula, 20 minutes before the onset of hypoxia and was continued for the remainder of the perfusion. Hypoxia was established by substituting 95% N2 and 5% CO2 + CO2 in the gas mixture. The alfa-tocopherol-treated rabbits hearts were protected in that during hypoxia and particularly during reoxygenation had a lower rate or rise of resting tensions and of ATP and CP depletion. This treatment also maintained mitochondrial function after hypoxia and reoxygenation and it resulted in the preservation of the fine ultrastructure of the myocardium as electronmicroscopic examination of the hearts revealed a marked reduction in oedema, contracture-band formation and mitochondria alterations.

Aerobiosis↗
PubMed1982

Myocardial mitochondrial functions in alpha-tocopherol-deficient and -refed rabbits.

In mitochondria from alpha-tocopherol-deficient rabbit hearts (30 days), there was a close correlation between the decline in respiration and the incidence of membrane peroxidation. In the same mitochondria, an increased formation of oxygen radicals was also observed, whereas superoxide dismutase activity was only slightly depressed. The exposure of mitochondria to exogeneous oxygen radicals generated by a xanthine-xanthine oxidase system caused a marked decrease in their oxidative phosphorylation capacity associated with an increase in lipid peroxidation breakdown. This was particularly evident in mitochondria from alpha-tocopherol-deficient rabbits. In mitochondria from deficient animals that had been rehabilitated with alpha-tocopherol, the toxic effect of oxygen radicals was less evident.

Adenosine Diphosphate↗
PubMed1982

Optokinetic visual detection in the rat visual centres. A [14C]-2-deoxy-D-glucose study.

Following forty-five min of binocular optokinetic stimulation (OKS) the autoradiographic maps of [14C]-2-deoxy-D-glucose (2DG) assumption of Long-Evans brain reveal clearly different patterns of optical density within visual centres. The most superficial layers of superior colliculus (SC) and a pretectal area including the nucleus of the optic tract (NOT) appear symmetrically, strongly darker than other visual structures such as lateral geniculate nucleus (LGN) and visual cortex (VC). Whereas the lack of metabolic increase at LGN and VC levels entirely confirms the non-involvement of the geniculo-cortical path in mediating the optomotor response following OKS in Rodents, it is postulated that the symmetrical increase of 2DG uptake even upon unidirectional OKS found even at pretectal level may represent a commissural transfer of visual information between homologous pretectal areas like the nuclei of the optic tract.

Animals↗
PubMed1981

[Free perforation by primary and localized hodgkin's disease of the small bowel (author's transl)].

The observation of a case of Hodgkin's disease primarily localized in the small bowel and with clinical picture of free perforation prompts the AA. to report the unusual enteric symptoms of this disease and to examine its pathologic and clinical features. Although Hodgkin's disease of the small intestine as a cause of perforation is extremely rare, the AA. describe the prominent frequency of abnormal serum proteins and of long lasting diarrhea with syndrome of florid malabsorption as primary manifestations of ileum involvement. Moreover the AA. indicate that while diagnosis of this peculiar location is rarely made clinically, it requests laparotomy and its confirmed by histologic specimen. The AA. suggests radical surgery and extensive radiotherapy in the treatment of primary Hodgkin's disease of the small bowel.

Adult↗
PubMed1981

[Heart muscle mitochondria function in alpha-tocopherol deficient rabbits. (author's transl)].

In the mitochondria of alpha-tocopherol deficient rabbit hearts (30 days) there was a close correlation between the decline in respiration and the incidence of membrane peroxidation. The intraperitoneal injections of alpha-tocopherol (25 mg/kg) from the the 28th day to the 30th day to the vitamin E deficient rabbits prevented a decline in either the mitochondrial respiratory or in the lipid peroxidation breakdown. The addition of alpha-tocopherol "in vitro" to the alpha-tocopherol deficient cardiac mitochondria failed to improve their function. As a result of this study, the possibility that the alpha-tocopherol may protect the cardiac mitochondrial activity by preserving their integrity appears to be consolidated.

Animals↗
PubMed1981

Interaction between heparin and adriamycin in mice bearing the Lewis lung carcinoma.

The investigation was prompted by the observation that adriamycin can interact with heparin in vitro and reduces its anticoagulant activity in ex vivo tests in humans. The possible interactions between these two drugs were studied in C57Bl/6J mice bearing the Lewis Lung Carcinoma (3LL). The anticoagulant activity of heparin was temporarily reduced by concomitant treatment with adriamycin, as indicated by both activated partial thromboplastin times and blood recalcification times. In contrast, no changes were found in the kinetics of adriamycin disappearance from blood and accumulation in tissues if mice had been pretreated with heparin. Moreover, the effect of adriamycin on tumour and metastasis growth was unchanged by the association with the anticoagulant. These data indicate that the short-lived interaction between adriamycin and heparin, which can be documented by coagulation tests, does not necessarily involve a modification in the anticancer activity of the anthracycline.

Animals↗
PubMed1980

[Phenoxybenzamine antagonism of ergometrine-induced increase of coronary artery resistance in rabbits].

Ergometrine is currently used as a test for Prinzmetal variant angina, causing specifically a coronary artery spasm in these patients, even if the mechanism of this drug on coronaries is still unclear. In isolated rabbit heart perfused at constant flow the administration of ergometrine at the concentration of 2.2 x 10(-5) M evoked a marked and longlasting increase of coronary resistance which was revealed by a rise in perfusion pressure from 68.2 +/- 12.9 to 124.4 +/- 21.7 (m +/- SD; n=21). This increase appears only with repeated perfusions of the drug and moreover it was not reproducible in the same preparation after its maximal response. The vasoconstriction was not significantly affected either by atropine or mepyramine, but it was strongly reduced by the phenoxybenzamine pretreatment (2.9 x 10(-6) M; n=8). It is evident the role of alpha-adrenergic receptors in ergometrine effect, but our results do not allow to understand its true mechanism, in fact the noradrenaline release can not be completely excluded.

Animals↗