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A Lucić

Publications and source records attributed to A Lucić.

At least 19 recordsLinked to original sources

Changes in plasma lipids after a non-lethal dose of cycloheximide in rats.

This paper describes a study of the effect of a single intraperitoneal non-lethal dose of cycloheximide (CHM; 2.0 mg/kg body weight) on the concentration of plasma lipids and lipoproteins in male rats killed one, two, three, four and nine days after receiving the dose. The concentration of triglycerides, total cholesterol, high-density lipoproteins (HDL)-cholesterol and low-density lipoproteins (LDL)-cholesterol was measured in treated and control animals. The effect of CHM on the concentration of triglycerides, total cholesterol, HDL-cholesterol, and LDL-cholesterol was visible in rat plasma throughout the study. Total cholesterol and HDL-cholesterol concentrations showed the same pattern of changes, probably due to the reversible inhibition of apolipoprotein apo A-I synthesis by CHM. The concentration of triglycerides decreased after a lag period of three days when the reserves of apolipoprotein apo B, the main apolipoprotein of very low-density lipoproteins (VLDL)-cholesterols produced in the liver, were consumed.

Animals↗

Variations of ochratoxin A concentration in the blood of healthy populations in some Croatian cities.

The nephrotoxic mycotoxin ochratoxin A (OTA), a common contaminant of cereals, has been implicated in the etiology of endemic nephropathy. It was also frequently found in low concentrations in blood of healthy populations in countries where endemic nephropathy is not known. However, data on regional and seasonal differences in the frequency and concentration of OTA in human blood are scarce. In June, September and December 1997, and March 1998, about 50 human blood samples were collected randomly from blood donors for blood banks in the Coatian cities of Osijek, Rijeka, Split, VaraZdin and Zagreb. OTA was measured in the total of 983 samples using an HPLC technique with fluorescent detection. The daily intake of OTA was estimated from the mean concentration found in different cities and at different times of year. Samples containing OTA above the detection limit (0.2 ng/ml of plasma) were found in populations from all Croatian cities at all collecting periods. The highest frequency (59%) of samples containing OTA above the detection limit and the highest mean concentration (0.39 ng/ml) were found in June. Both the frequency and the mean concentration were lowest in all samples in December (36% and 0.19 ng OTA/ml, respectively). Osijek was the city with the highest frequency of OTA-positive samples (81%) and the highest mean OTA concentration (0.56 ng/ml). The total mean concentration of OTA in blood of healthy population in Croatia is lower (0.30 ng/ ml) than the mean concentration in European countries as a whole (0.90 ng/ml). The estimated daily intake, calculated from the mean concentration in all blood samples, is 0.40 ng OTA/kg body weight, which is much lower than that proposed by World Health Organization as the tolerable daily intake (16.0 ng/kg body weight). Healthy populations of Croatia are exposed to low, but seasonally and regionally variable amounts of OTA.

Chromatography, High Pressure Liquid↗

The occurrence of ochratoxin A in blood in general population of Croatia.

The exposure of general population in Croatia to mycotoxin ochratoxin A (OTA) was investigated in five cities: Split, Rijeka, Varazdin, Osijek, and Zagreb. In June 1997, blood donors from each of these cities gave 50 samples of 3 ml plasma each. The mean concentration of OTA, determined using high-pressure liquid chromatography (HPLC), was 0.39 ng/ml of plasma. The highest frequency of OTA-positive samples (>0.2 ng/ml plasma), and the highest number of samples with the concentration exceeding 1.0 ng/ml, were found in Osijek. This difference is probably due to the higher consumption of fresh and dried pork by population of Osijek. The calculated daily intake of OTA, estimated from the mean OTA concentration of all samples in each town (in the range from 0.24 to 0.91 ng/kg b.w. found in Rijeka and Osijek, respectively) is lower than the tolerable daily intake proposed by Joint FAO/WHO Expert Committee on Food Additives (1995) of 16.0 ng OTA/kg b.w.

Chromatography, High Pressure Liquid↗

Toxic effects of mycotoxins in humans.

Mycotoxicoses are diseases caused by mycotoxins, i.e. secondary metabolites of moulds. Although they occur more frequently in areas with a hot and humid climate, favourable for the growth of moulds, they can also be found in temperate zones. Exposure to mycotoxins is mostly by ingestion, but also occurs by the dermal and inhalation routes. Mycotoxicoses often remain unrecognized by medical professionals, except when large numbers of people are involved. The present article reviews outbreaks of mycotoxicoses where the mycotoxic etiology of the disease is supported by mycotoxin analysis or identification of mycotoxin-producing fungi. Epidemiological, clinical and histological findings (when available) in outbreaks of mycotoxicoses resulting from exposure to aflatoxins, ergot, trichothecenes, ochratoxins, 3-nitropropionic acid, zearalenone and fumonisins are discussed.

Adult↗

Ochratoxin A in blood of healthy population in Zagreb.

Healthy blood donors from the city of Zagreb were checked for the presence of a nephrotoxic mycotoxin ochratoxin A (OTA) in the plasma. Samples of blood were collected in June, September, and December 1997, and March 1998, totalling 200 or 50 in each round. The concentrations of OTA were measured using high pressure liquid chromatography (HPLC) method (detection limit 0.2 ng OTA/ml of plasma). The frequency of OTA-positive samples (> 0.2 ng/ml of plasma) showed significant seasonal variation (P < 0.001). The frequency of OTA-positive samples was the highest in March (65%) and it gradually decreased towards December (12%). The high frequency of positive samples coincided with seasons favouring growth of moulds and production of toxins. The daily intake of OTA by healthy persons in Zagreb was estimated from the mean concentration of OTA in samples collected during the whole year (0.19 ng OTA/ml plasma). The estimated daily intake was 0.26 ng/kg b.w., that is, substantially below the tolerable daily intake proposed by World Health Organization (16.0 ng/kg b.w.).

Chromatography, High Pressure Liquid↗

Quinuclidinium-imidazolium compounds: synthesis, mode of interaction with acetylcholinesterase and effect upon Soman intoxicated mice.

Four compounds were prepared: 3-oxo-1-methylquinuclidinium iodide (I), 2-hydroxyiminomethyl-1,3-dimethylimidazolium iodide (II) and two conjugates of I and II linked by -(CH2)3- (III) and -CH2-O-CH2- (IV). The aim was to evaluate separately the properties of I and II as opposed to III and IV, which contain both moieties in the same molecule. All four compounds were reversible inhibitors of acetylcholinesterase (AChE; EC 3.1.1.7). The enzyme/inhibitor dissociation constants for the catalytic site ranged from 0.073 mM (II) to 1.6 mM (I). The dissociation constant of I for the allosteric (substrate inhibition) site was 4.8 mM. Possible binding of the other compounds to the allosteric site could not be measured because II, III and IV reacted with the substrate acetylthiocholine (ATCh) and at high ATCh concentrations the non-enzymic reaction interfered with the enzymic hydrolysis of ATCh. The rate constants for the non-enzymic ATCh hydrolysis were between 23 and 37 l/mol per min. All four compounds protected AChE against phosphorylation by Soman and VX. The protective index (PI) of I (calculated from binding of I to both, catalytic and allosteric sites in AChE) agreed with the measured PI; this confirms that allosteric binding contributes to the decrease of phosphorylation rates. The PI values obtained with III and IV were higher than those predicted by the assumption of their binding to the AChE catalytic site only. The toxicity (i.p. LD50) of compounds I, II, III and IV for mice was 0.21, 0.68, 0.49 and 0.77 mmol/kg body wt. respectively. All four compounds protected mice against Soman when given (i.p.) together with atropine 1 min after Soman (s.c.). One-quarter of the LD50 dose fully protected mice (survival of all animals) against 2.52 (IV), 2.00 (I and III) and 1.58 (II) LD50 doses of Soman.

Acetylcholinesterase↗

Ochratoxin A in human sera in the area with endemic nephropathy in Croatia.

Ochratoxin A (OA) is nephrotoxic fungal metabolite (mycotoxin) occurring in foodstuffs. The compound is causally associated with mycotoxin porcine nephropathy, a disease comparable with a human kidney disease called endemic nephropathy (EN). In this paper we presented results obtained over a 10-year period in the hyperendemic village Kaniza, and in control villages where no clinical cases of nephropathy had been found. In the hyperendemic village Kaniza and non-endemic villages the incidence of OA in human blood was up to 4.5% (range 2-50 ng/ml) and up to 2.4% (range 2-10 ng/ml), respectively. Almost all samples of food and feed, collected randomly in the hyperendemic village were found to contain OA. Considering marked exposure to OA in Kaniza, it was assumed that incidence of EN in this population could be related to OA contamination of food and feed.

Animal Feed↗

Antidotal efficacy of quinuclidinium oximes against soman poisoning.

The efficiency of newly synthesized oxime derivatives of quinuclidinium were tested in vitro on soman inhibited acetylcholinesterase (AChE) of human erythrocytes and in vivo using soman poisoned mice. For this purpose, the inhibitory power of oximes (IC50), acute toxicity (LD50) as well as reactivating and protective capacities with respect to soman-inhibited AChE were determined for each of the oximes. All oximes tested were ineffective in vitro but protected mice very efficiently (BM-1 protects against 4LD50 of soman). The results indicate that the in vivo effectiveness of quinuclidinium oximes against soman poisoning may not be related to reactivation or protection of AChE but rather to some other mechanism of the cholinergic system.

Acetylcholinesterase↗

[Successful treatment of acquired F:VIII C inhibitor after delivery using plasmapheresis and high doses of immunoglobulins].

Three months after delivery a patient 34 years of age was admitted to the Clinic of haematology in Novi Sad because of sudden massive bleeding from the left ankle, left lower leg as well as for having small haematomas visible at forearms. Examining the mechanism of haemostasis, a diagnosis was made: acquired inhibitor VIII:C coagulation factor. Concentrate of VIII coagulation factor was used in treatment, as well as plasmaphaeresis, high doses of immunoglobulins and immunosuppressive drugs: prednisone and azathioprime. The result was a very quick recovery of the clinical state with loss of inhibitor to VIII: C coagulation factor. Three years after the treatment the patient has no difficulties and no antibodies to VIII:C coagulation factor.

Adult↗

Intensity of thrombin activity and surgical trauma.

Increased level of in vivo thrombin activity represents the essential mark of prethrombotic state. In order to assess the influence of surgical trauma on the constitution of prethrombotic state immediately after the surgical intervention, dynamic estimations of fibrinopeptide A (FPA) have been done in a group of 18 patients who had undergone abdominal surgery and in the group of 25 patients who underwent the replacement of artificial hip, and who were on preventive treatment with subcutaneous heparin. At the same time the presence of soluble fibrinmonomer complex and, in the group of patients on heparin treatment, the concentration of plasma heparin were examined. The investigations were done before the surgical intervention and on the first, third and seventh postoperative day. Our dynamic study showed the existence of certain relation between the surgical trauma and values of FPA which were the expression of intensity of in vivo thrombin activity. The mean values of FPA increased markedly on the first postoperative day in comparison with the preoperative levels. On the third postoperative day significant reduction of FPA was observed and on the seventh day marked increase was found only in patients who were not on heparin prevention. Although preventive application of subcutaneous heparin did not affect the whole blood coagulability it showed a suppressive impact on the thrombin activity level in examined surgical patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

[Evaluation of certain hemostasis parameters in premature infants].

In order to evaluate the specificity of hemostatic mechanism in premature Infants, the following examinations of coagulation and fibrinolytic parameters have been done: platelet number, concentrations of fibrinogen prothrombin, factors V, VII X, X, VIII, IX and XIII, antithrombin III, plasminogen, euglobulin lysis time, fibrin degradation products, alpha-1 antiplasmin and alpha-2 macroglobulin. The examinations have been done in the whole of 18 premature infants of both sexes. The obtained results show that lowered level of coagulant activity was not exclusively the consequence of low activity of vitamin-K dependent factors, but the result of more complex disorders partly connected with the transient reduction of factors VIII, XIII and fibrinogen. The total fibrinolytic activity, in the meantime, was of the normal intensivity. The established disorder of coagulation-fibrinolytic balance probably represents the certain contributing factor in more frequent occurrence of haemorrhagic syndrome in premature infants.

Antithrombins↗