Defining the Modalities of Intravenous Contrast Application During the Diagnostics of Hepatic Metastases with Computerized Tomography.

INTRODUCTION: The liver is the biggest human abdominal parenchymal organ; it weights approximately 1500 grams and is located in the right hypochondrium, under the diaphragm. Liver is able to perform multiple functions also by means of the rich dual vascularization: hepatic arterial system and the portal vein system, between which exists a short circuit (shunt) and free mixture inside the sinusoid, whilst the two flows drain in the same vein system. The discovery of CT and its application in practice fundamentally changes the importance of diagnostic methods for hepatobiliary lesions. PATIENTS AND METHODS: During a 4-year period, 984 patients suspected with liver or biliary tract disease were explored with CT. 117 of these patients were analyzed with liver metastases. Examinations of the liver was performed in dorsal decubitus and in absolute apnea with spiral movement of the table and in denominations of 1and 5 mm. Siemens MSCT 64 and 6 tier apparatuses enable short scanning time with almost immediate reconstruction, which offers all the necessary elements required for carrying out certain protocols. RESULTS: The average density of metastatic lesions is about 20 HU smaller than normal liver parenchyma. Metastasis with necrosis are more hypodense (30-50 HU smaller than normal liver parenchyma), whilst necrotic metastases with smaller dimensions are almost isodense with normal parenchyma. However, metastases with diameter between 4 to 6 cm are completely isodense and will remain so even after the application of I.V. contrast. The average more frequent size according to most authors, as well as according to our material (148 patients or 90%) was 2-3 cm in transversal diameter.

Development of receptor bronchial system in isolated preparation of piglet trachea in vitro.

In this paper we present the flow research of the development of receptor bronchial system in the first month of extra-uterine life up to the sixth month of development, performed by tracking the reactions of isolated tracheal rings in acetylcholine (Ach), propranolol (P), histamine (Hist), and prostaglandin (PGF2-alfa) in concentrations of: 10-4, 10-3, 10-2 and 10-1 mol/dm3; in piglets of ages: 1 month, 2 months, 4 months and 6 months. Results shows that Ach causes reaction of smooth muscles from the first month of extra-uterine life (p < 0.01) and that Propranolol (P) significantly emphasizes the effect of Ach (p > 0.1), while histamine and PGF2-alpha do not cause constriction (histamine up to 4 months of age, PGF2-alfa up to 6 months of extra-uterine life). This shows that cholinergic and adrenergic system in piglet airways is developed during intrauterine life and reaction can be registered in the first month of extra-uterine life, while other receptor systems are developed in later periods of extra-uterine life. This suggests that lack of reaction of tracheal smooth musculature (TSM) comes as a result of sufficient non-maturity of mast cells from which chemical mediators, with local functioning, are released.

Role of meconium in the reaction of airways smooth musculature in the newborn with meconium aspiration syndrome (MAS).

The role of meconium in the respiratory system was studied in newborns, who died from various causes (250 up to 3000 g of weight). We monitored tracheal rings response to dopamine, serotonin and ethanol in different concentrations (dopamine: 0,05 mg/ml, 0,5 mg/ml, 5 mg/ml; serotonin (5-HT): 10-4, 10-3, 10-2, 10-1 mol/dm3; ethanol: 0,02 ml, 0,5 ml, 1,0 ml; 96%). Tracheal smooth musculature tonus (TSM) was examined in 48 tracheal preparations taken after the newborn exitus due to different reasons. Based on functional researche of isolated preparations of tracheas, it may be concluded that: aspiration of meconium has not changed the response of TSM to dopamine, serotonin and ethanol (p>0,1) in comparison with the control group, which have died due to different lung inflammatory processes (e.g. pneumonia, bronchopneumonia, atelectasis, cerebral hemorrhage). The results suggest that meconium does not potentiate the constricting action of dopamine, serotonin and ethanol in tracheobronchial system. Meconium causes mild relaxation of the TSM through a mechanism that is not intermediated by the products of cyclooxygenases (prostaglandins, prostacyclins) from the tracheal epithelium or proteins. Also, as it seems, the direct activity of many tested acids in the smooth musculature has no significant impact on increase of the airways tonus in MAS syndrome.

Postnatal - physiological research of the bronchial receptor system development on the isolated preparation of the human trachea in vitro.

Research was done on pharmacological-physiological development of the bronchial receptor system on the smooth muscles of trachea in the newborn children, alive-born and stillborn children. Monitored was the response on: acetylcholine, dopamine, histamine and serotonin in different molar concentrations 10(-4), 10(-3), 10(-2), 10 mol/dm(-3), micromol/dm(-3)). Research was done on tonus of tracheal smooth muscles of 23 tracheal preparations taken by autopsy after death from different factors. Based on pharmacological-physiological research on the preparations of human isolated trachea it was find out that: acetylcholine stimulation effect is significant (p>0,01) in 38-41 weeks of pregnancy comparing with that in 30-37 weeks of pregnancy (p>0,01), while dopamine stimulation effect is significant (p>0,05) in 30-37 pregnancy weeks comparing with the effect of acetylcholine and dopamine on the still-born infants of the same pregnancy period (p<0,01). Histaminic receptors were developed during intrauterine life after 38 weeks of pregnancy (p>0,025). Serotonin has caused contraction of the bronchial smooth muscles after 30 pregnancy weeks, but response was not significant (p<0,01). This suggests that cholinergic and adrenergic system of the airways in alive newborn infants develops in parallel intrauterine, contrary to other systems which develop in certain extrauterine life phases.