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C Duca

Publications and source records attributed to C Duca.

7 recordsLinked to original sources
PubMed1981

Ultrastructural changes of the hypertrophic epithelial cells in the thymus of splenectomized chickens.

Three weeks following the splenectomy of young chickens an increased number of the hypertrophic epithelial cells, which presented various signs of secretory activity, could be observed in the thymus. After splenectomy, these cells usually present a single, large-sized intracytoplasmic vesicle or vacuole lined with microvilli. The lumen of such vesicles is always full of granulated and membranous material. The ultrastructural appearance of the hypertrophic epithelial cells strongly suggests an intensive metabolic activity and a possible active protein synthesis. These results lead to the hypothesis that hypertrophic epithelial cells secrete a lymphopoietic hormones which is active in normal chickens and which is secreted at an accelerated rate during certain hyperfunctional circumstances such as the period following splenectomy.

Animals↗
PubMed1978

Improvement of perfusion flow in the isolated rat liver under the influence of streptase. Autohistoradiographic aspects of 125I-labelled fibrinogen deposition.

The dynamics of the fibrinoplastic process were studied in rat isolated liver, perfused in normothermia with a synthetical medium. For the autohistoradiographical study, 125I-labelled fibrinogen was added to the perfusing medium. The historadiograms obtained suggest that the main link in the rise of trans-hepatic vascular resistance is thickening of the fibrin muff of the sinusoids. Consequent reduction of the capillary permeability determines favourable conditions for stasis and massive precipitation of fibrinogen under the form of fibrin thrombi into the intrahepatic vessels. Streptase addition to the perfusion medium prevents the intervention of these mechanisms during the studied period.

Animals↗
PubMed1976

Improvement of perfusion-flow in the isolated rat liver, under the influence of streptase.

Accumulation of radioactive material in the isolated rat liver was noted when 125I-fibrinogen was added to the perfusing medium. Owing to an enhanced production of fibrinogen and to a diminished fibrinolysis, fibrin deposits were found to occur in the capillaries of fhe isolated liver. This would cause a decrease of hepatic flow and an impairment of the nutrition of this organ which leads to subsequent necrosis. Administration of streptase removed the fibrin deposits and restored the perfusive flow in the isolated liver.

Animals↗
PubMedDate not supplied

[Preservation of rat liver using prolonged perfusion with a complex solution lacking hemoglobin].

The author's aim was to investigate conservation of rat liver by continuous perfusion of the isolated organ in conditions of normal temperature, as well as in hypothermia. A complex solution was used, lacking hemoglobin. Over a period of 5 hours of conservation the authors evaluated the perfusion rate, the concentration of lactate and pyruvate in the conservation medium, while on histological preparations was investigated the formation of fibrin deposits in the intra-hepatic vessels. The results confirmed the positive effects of hypothermia, that is not due exclusively to a limiting of the metabolic necessities of the organ but also to a reduction of the fibrinogenesis and a slowing down of the formation of intra-hepatic microaggregates.

Animals↗
PubMedDate not supplied

[Improvement of the conditions of rat liver preservation by concomitant perfusion of the liver and kidney].

One of the factors limiting the duration of rat liver storage is the excessive accumulation of catabolites in the perfusion medium. In view of obtaining of an efficient depuration the authors have introduced a new circuit allowing for the concomittant perfusion of the liver and of the kidneys. The excretion effort of the kidneys is assessed by the estimation of urea nitrogen in the perfusion medium and in the urine collected over the entire duration of the experiment. The results have confirmed the good function of the system which provides possibilities for improved storage conditions of rat liver.

Animals↗