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The challenge to predict the direction of market requirements is an increasingly pronounced challenge of today’s management structures, i.e., how to make timely decisions that ensure the sustainability of the business. In predicting when and where the potential for success will arise or what the sources of threats will be, it is essential to properly implement and continuously use the early warning system by monitoring indicators from the environment. This paper presents a theoretical and practical contribution to understanding the importance of early warning systems in Croatian companies operating in international markets. The introduction includes a discussion on current business conditions, and then the term “early warning system” is conceptually discussed. The research part of the paper presents the results of empirical research on the perception of respondents on the level of development of early warning systems in their companies operating in the international market according to the legal form, size, headquarters, and ownership of the company. The established attitude of the respondents was that the level of development of the early warning system is low, i.e., that they are used primarily by large foreign-owned companies based in more economically developed counties.

Abstract: The aim of the study was to analyze the course and outcome of pregnancies with congenital heart disease of the fetus, diagnosed and terminated at the Institute of gynecology and obstetrics Clinical Center of Serbia over four years. The study included 71 patients, divided into 3 groups according to the fetal outcome. Group 1 had consisted of 9 pregnancies terminated artificially, Group 2 of 48 patients who delivered live fetuses, and Group 3 of 14 pregnancies terminated as fetal intrauterine death. The types congenital heart diseases were categorized as follows: 40 had L-R shunting type, 18 R-L shunting type, 8 coartacion of aorta, and 7 valvular diseases. Intrauterine fetal death occurred in 11 pregnancies in Group 3 after 28 weeks of gestation. In 13 cases karyotypisation were done, because of maternal age or intrauterine growth retardation diagnosed with ultrasound, and 9 of them had genetic disorders. Forty-eight fetuses were born alive. Fourteen died in the first 2–7 days and 12 had successful heart surgery. Twenty-two needed no surgical correction. Ultrasound findings were false negative in 3 cases. The diagnosis of fetal heart disease should be done by fetal echocardiogram, which can be preformed early in the beginning of the pregnancy.

Abstract: Adult male Wistar rats were subjected to propranolol (P, 0.40 mg/100 g/day) or saline (S) administration (controls) over 14 days. The expression of major differentiation molecules on thymocytes and Thy-1 (CD90) molecules, which are shown to adjust thymocyte sensitivity to TCRαβ signaling, was studied. In addition, the sensitivity of thymocytes to induction of apoptosis and concanavalin A (Con A) signaling was estimated. The thymocytes from P-treated (PT) rats exhibited an increased sensitivity to induction of apoptosis, as well as to Con A stimulation. Furthermore, P treatment produced changes in the distribution of thymocyte subsets suggesting that more cells passed positive selection and further differentiated into mature CD4+ or CD8+ single positive (SP) TCRαβhigh cells. These changes may, at least partly, be related to the markedly increased density of Thy-1 surface expression on TCRαβlow thymocytes from these rats. The increased frequency of cells expressing the CD4+25+ phenotype, which has been shown to be characteristic for regulatory cells in the thymus, may also indicate alterations in thymocyte selection following P treatment. Inasmuch as positive and negative selections play an important role in continuously reshaping the T-cell repertoire and maintaining tolerance, the hereby presented study suggests that pharmacological manipulations with β-AR signaling, or chemically evoked alterations in catecholamine release, may interfere with the regulation of thymocyte selection, and consequently with the immune response. (Mol Cell Biochem xxx: 1–13, 2005)

To elucidate a putative role of β-adrenoceptors in the modulation of intrathymic T-cell maturation, the expression of major differentiational antigens (CD4/CD8 and TCRαβ) on the thymocytes from both immature (aged 21 day at the beginning of the treatment) and adult (aged 75 days at the beginning of treatment) male rats subjected to a 15-day-long propranolol treatment (0.40 mg/100 g/day, s.c.) was analyzed by two- and one-color flow cytometry, respectively. Rats of matched age injected with saline served as controls. The propranolol treatment in immature but not adult rats caused a significant reduction in both the relative thymus weight and total thymocyte yield. In addition, a significant increase in the percentage of CD4+8+double-positive cells, with a proportional decrease in the relative proportion of CD4+8−single positive cells, was found in immature rats. In contrast, a slight but significant decrease in the percentage of CD4+8+cells with a parallel increase in the relative proportion of CD4+8−cells was found in adult rats. In both groups of rats, the percentage of TCRαβtotalthymocytes was increased: in immature rats this was due to an increase in the percentage of TCRαβlowthymocytes, while in the adult rats it reflected a rise in the relative proportion of TCRαβhighcells. In conclusion, the study revealed that propranolol treatment in both immature and adult rats alters the relative proportion of CD4+8+and CD4+8−thymocytes, but in opposite fashion, and the data suggest that this treatment affects distinct fractions within the population of CD4+8+thymocytes with respect to expression of TCRαβ. The results also indicate that, regardless of rat sexual maturity, the development of thymocytes towards CD4−8+T-cells is relatively insensitive to long-lasting β-adrenoceptor blockade.

In the light of the mutual dependence between the adrenal cortex and medulla, the aim of this work was to examine whether glucocorticoid treatment of pregnant rats affects the development of the adrenal medulla of their offspring in the postnatal period. Pregnant rats were treated with dexamethasone (Dx) in a daily dose of 0.3 mg Dx/kg b. w. during days 16–20 of gestation. The structure and function of the adrenal medulla of their 14-day-old offspring were estimated on the basis of the morphometric parameters of the gland, chromaffin cell mitotic index and adrenal gland adrenaline content. Stereological analysis was carried out at the light microscopic level, the mitotic index was determined by counting the number of metaphase arrested chromaffin cells following the administration of vincristine-sulphate, whereas adrenaline content in the adrenal gland was measured fluorimetrically. Plasma ACTH concentrations of the offspring were also determined by RIA. Long term Dx treatment of pregnant rats caused a significant decrease of the total volume of adrenal chromaffin tissue in the 14-day-old offspring as well as a reduction in the number of chromaffin cells and the average cell and nuclear volumes. The proliferative activity of the chromaffin cells was also lower than in the control offspring. These changes were accompanied by a significantly reduced adrenaline content in the adrenals. The results of this work show that glucocorticoid excess during the period of pregnancy when the fetal adrenal medulla is formed has a strong inhibitory effect on the adrenal medulla of the offspring at the age of 14 days.

Abstract: An optimization of mortar (as matrix), improved with bentonite clay, used for immobilization of radionuclides60Co,137Cs,85Sr and54Mn, is presented. A relatively simple mathematical model is given, which permits minimization of leach rate and permeability and maximization of compressive strength. An optimal solution, based on experimental data, is given. These results will be used for a future Yugoslav radioactive waste storing center.

Abstract: Results are presented of a series of experimental tests performed to determine the influence of matrix characteristics on the leaching mechanism of copper aluminium oxychloride immobilized into cement matrices. The objective of this research was to investigate the leaching mechanism of copper as a constituent of copper aluminium oxychloride (ldquoCAOXrdquo).

The aim of these examinations was to determine the influence of dexamethasone (Dx)-treatment of gravid females, on day 16 of gestation on the development of medullary chromaffin tissue of their fetuses and neonatal offspring. In conducting these investigations we used stereo-logical as well as spectrofluorimetric measurements, in 20-day-old fetuses and 1 -, 3-, 5-, 7-, 9-, 11-, 13- and 14-day-old neonatal rats. Single Dx-treatment (1.5 mg/kg bw) of the dams led to a significant decrease in body and adrenal weight of their fetuses and neonatal offspring, and also reduction of the medullary volume and the number of chromaffin cells during the entire period examined as a result of decreased cell proliferation in the fetal and early neonatal period (till the 5th day of age). The proliferative activity of the chromaffin cells was evaluated through the mitotic index after applying the cytostatic vincristine-sulphate. During the second neonatal week the mitotic index showed significantly higher values in comparison with the corresponding controls, which indicates that there is regeneration and recovery of the adrenal gland medulla. Adrenaline content in the adrenal gland tissue of offspring of Dx-treated dams was significantly reduced only on the 1st neonatal day. Thus, the change in blood glucocorticoid level of pregnant females after a single Dx injection during the period critical for development of the hypothalamo-pituitary-adrenal system in fetuses affects the development and kinetics of medullar chromaffin cell division.

Abstract: Leaching of137Cs from ion-exchange resin incorporated in cement and bitumen composite using two methods based on theoretical equations has been developed. These were: Method I, diffusion equation derived for a plane source model1 and Method II, empirical model employing a polynominal equation2,3. Results presented in this paper are examples of data obtained in a cement and bitumen testing project which will influence the design of a future radioactive waste storage center.

Abstract: A technique for leaching137Cs and60Co from a cement matrix, using three methods based on theoretical equations, has been developed. These were: Method I, diffusion equation derived for a plane source model, Method II, rate equation for diffusion coupled with a first-order reaction. The leaching data were also analyzed by an empirical method employing a polynomial equation, Method III. Results presented in this paper are examples of data obtained in a cement testing project which will influence the design of the future radioactive waste storage center.

Abstract: To assess the safety of disposal of a radioactive waste-cement composite, the leaching of137Cs from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA.1 The leachability was measured as a function of bentonite clay to cement ratio. The fraction of137-Cs leached from a specimen of Portland cement is 0.03–0.13 at a leaching time of 400 d. Results presented in this paper are examples of data obtained in a 10 y mortar and concrete testing project, which will influence the design of the engineered trench system for a future Yugoslav radioactive waste storage center.2,3

Abstract: Determination of retardation factors and coefficients of distribution using a simplified mathematical model for analyzing the migration of leachate and radioactive material contained in radioactive waste burial concrete trench systems has been developed. Results show that concrete for engineered trench systems secures radionuclide preservation in solidified medium for longer than 300 years. These results will be used for constructing future radioactive waste storing centers in Yugoslavia.

The effects of prolonged dexamethasone (Dx) administration to pregnant rats on the struture and function of the adrenal glands of fetal and neonatal offspring have been investigated by combined stereological and ultrastructural methods, as well as by metaphase index determination. Pregnant rats were injected subcutaneously with Dx (0.3 mg/kg body weight/day) during 5 days, starting from day 16 of gestation. The dams and their fetuses were killed 24 hr after the last injection. The neonatal offspring were killed in the same way on the 3rd and 14th day of life. Because in fetal and 3-day-old neonatal rats zona reticularis (ZR) was poorly defined and could not be clearly seen as a separate zone, zona fasciculata (ZF) and ZR were analyzed as one, inner zone (IZ). In 14-day-old rats ZF and ZR were analyzed separately. Proliferative activity of adrenocortical cells was estimated following the application of Vincristine sulphate. Dx treatment of pregnant rats induced a marked decrease of fetal adrenal gland volume and the volumes of zona glomerulosa + capsula (ZG + C) and IZ as the consequence of atrophic changes in the gland and reduction of the average volume and total number of adrenocortical cells. Similar morphometric changes were found in 3- and 14-day-old pups. However, in 3-day-old animals the number of cortical cells in the ZG was increased, whereas on the 14th postnatal day cortical cell number remained decreased only in the ZF. The multinuclear giant cells, numerous lymphocytes, and the resorption zones, present in the adrenal cortex of fetuses and 3-day-old pups of both experimental and control dams, were not seen in 14-day-old offspring. These results demonstrate that prolonged treatment of pregnant rats with Dx in the period when intensive differentiation of the fetal hypothalamo-hypophyseal system takes place inhibits proliferative activity of adrenocortical cells and evokes considerable atrophic changes in the adrenal glands of offspring from 20 days gestation to 14 days after birth. The histological appearance of the adrenal cortex and the ultrastructure of adrenocortical cells suggest that cortical cell function was inhibited, too.J. Exp. Zool. 279:54-61, 1997. © 1997 Wiley-Liss, Inc.

Abstract: To assess the safety of disposal of radioactive waste material in concrete, curing conditions and time of leaching radionuclide137Cs have been studied. Leaching tests in concrete were carried out in accordance with a method recommended by IAEA1.

Abstract: This paper presents results from studies made to determine the leachability of137Cs from immobilized evaporator sludge from a Pressurized Water Reactor with cement. Leaching of137Cs from cement matrix using three methods based on theoretical equations has been developed. These were: Method I, diffusion equation derived for a plane source model, Method II, rate equation for diffusion coupled with a first-order reaction. The leaching data were also analyzed by an empirical method employing a polynomial equation —Method III. Results presented in this paper are examples of data obtained in a cement testing project which will influence the design of a future radioactive waste storage center.