Volume 10 (2005)
Articles
VARIATIONS OF LEUKOCYTE SUBTYPES INDUCED BY LOW-FREQUENCY LOW INTENSITY MAGNETIC FIELD (50 Hz; 2.7 mT) EXPOSURE AND SULPIRIDE UNDER RESTRAINT STRESS IN THE RAT
LUCIAN HRIŢCU, CĂLIN MANIU, DANA HOROŞANU, CRISTIAN SORIN CÎMPEANU
Electromagnetic fields (EMF) became increasingly common constituent of the general and workplace environments early in the 20th century, but some lifestyles and occupations are associated with more than the average amount of exposure to electromagnetic fields. May patterns of exposure in the general and workplace environments be able to be identified with increased intensity and duration of exposure to electromagnetic field. The exaggerated rise on Na rates, K-ATPase, when the organism is subjected to EMF of 50-60 Hz, results in the increase of stress level on population subjected to this kind of produced radiation, mainly, by the proper home electrics or by workplace environment (Blank; Soo; Papstein, 1995). There is conflicting evidence about whether exposure to electromagnetic fields can directly alter the structure of DNA and chromatin. Most reviews have concluded that mutational and neoplasic transformation effects are not expected to happen (NRPB, 1992; ORAU, 1992; Tenforde, 1996; NRC, 1996). However, some reports suggest that electromagnetic fields may cause direct effects on the DNA (Lai and Singh, 1997). Even so, the population is not free of the low frequency EMF action, radiated from household appliances. At the last decade, there have been many studies of the possible relation between different kinds of cancer, like the child leukemia, brain tumors, lung cancer, breast cancer and lymphomas, among others and residential exposure to electromagnetic fields (Balcer; Elizabeth, 1995; Erren, 1997; Loomis, et al, 1994). Different studies reported epidemiological studies about the risks of cancer related to exposure to electromagnetic field (50/60 Hz) from powerlines (NRPB 1992; ORAU, 1992; Savitz, 1993; Health, 1996; Steveans; Davis, 1996; Tenford, 1996; NAS, 1996). Similar studies reported the risk of adverse effects on human reproduction associated to electromagnetic field (Chernoff, et al, 1992; Brent, et al, 1993; Shaw; Croen, 1993; NAS, 1996; Tenford, 1996). In later, more rigorous studies, Juutilainen et al. (1993) report significant early pregnancy loss from exposure to residential 50 Hz magnetic fields, but low numbers in the high-exposure group limit conclusions from this study. The truth is that, if it won't possible to confirm this correlation, it's not also conclusive the fact of that the electromagnetic waves are harmless when fall on live organisms, between a specific potency and frequency (Goldberg, 2000). Several reports have shown that exposure of rodents to ELF magnetic fields reduces the production, secretion or both of melatonin from the pineal gland (Reviewed by Reiter, 1997). Exposure of rats for 42 days to circularly polarized magnetic fields (0.02 and 0.1µT) reduced both day time and night time melatonin levels by 20-25% (Kato, 1994). The reduction on melatonin secretion and the increase on the ACTH and cortisol release are suggestive that the exposed builds to low frequency electromagnetic waves are more liable to high levels of stress and consequently, more liable to develop illness or organic imbalance.
THE HEMATOLOGICAL RESPONSE OF SOME CULTURE FISH UNDER NORMAL AND STRESS CONDITIONS
COSTICĂ MISĂILĂ, ELENA RADA MISĂILĂ
In intensive cultures, fish is permanently affected both by the aquatic environment itself and by the interventions required by the applied growth technologies. Whichever their nature, such stressing factors induce in the organism identical biochemical and hematological reactions. From a hematological viewpoint, fish' functional response to stress is reflected in the modification of the normal hemoglobin and hematocryte ratios (BEJERANO, 1984; KEBUS et al., 1992), of the erythrocytary constants, and, equally, in the numerical evolution of the red and white blood cells. (WLASOW and DABROWSKA, 1989). The present paper realizes a comparative analysis of the usual hematological indices in some farmed fish (rainbow trout - Oncorhynchus mykiss, common carp - Cyprinus carpio, silver carp - Hypophthalmichthys molitrix and grass carp - Ctenopharyngodon idella), under both normal and stress (i.e., alimentary, thermal, malady, a.s.o.) conditions.
SOME PRELIMINARY DATA ON THE ACTIVITY OF TOTAL AMYLASE, α- AND β-AMYLASE IN THE SMALL ROOTS AND STRAINS OF MILLET AND BRISTLE GRASS
ELENA CIORNEA, DUMITRU COJOCARU, GABRIELA VASILE
The process of seeds' germination has always aroused the interest of researches, if considering its special - both theoretical and practical - importance. This extremely complex process involves a multitude of biochemical and physiological processes through which the glucides, lipids and reserve proteins are mobilized for assuring the precursors necessary to the biosynthetic processes occurring in the embryo and in the future plant, up to the initiation of the photo-synthetic transformations. It may be assessed that, to some extent, the biochemical transformations occurring during germination are the reverse of the ones developed during seeds' maturation (and, respectively, during the formation of bulbs, tubercles, etc.) (TÃNASE et al., 1997). Following maturation, in the organs in which the reserve substances are deposited, the biochemical and physiological processes develop at a considerably lower rate, until reaching a minimum intensity, necessary to the maintenance of their vital capacity. In the moment when they are brought to optimum conditions of humidity, temperature, saline concentration, pH, etc., the reverse processes - which are mainly hydrolytic or phosphorolytic - begin to be manifested.
QUANTITATIVE DETERMINATION OF MUSCULAR GLYCOGEN IN ARISTICHTHYS NOBILIS AND HYPOPHTHAMICHTHYS MOLITRIX
GABRIELA VASILE, ELENA CIORNEA, DUMITRU COJOCARU, ELENA RADA MISĂILĂ, COSTICĂ MISĂILĂ
Glycogen, a polymer of α -D- glucose, represents the main reserve of glucides in animal organisms. The presence of glycogen has been evidenced in animal organisms, occurring in various stages of evolution. The form in which glucides are being deposited in tissues is, on one side, represented by glucose - which is the circulating glucidic component - and, on the other, by glycogen - the reserve glucidic compound. Generally, besides lipids and proteins, glucides represent indispensable sources of metabolic energy. Under conditions of constant abundance of alimentary glucides, animal organisms use to stock such substances, either as hepatic and muscular glycogen (the immediate stock of energy), or by their conversion in lipids from the adipose tissues (the future energy stock). In the case of fish, the normal values of muscular glycogen vary between 0.2 - 0.4 g %, while the values recorded by hepatic glycogen range between 7 and 11 g %; one has to observe here that, comparatively with mammals, these are much lower values. In fish, an important characteristic of glycogen and glucose is their high sensitivity to stress, starvation and diseases, high growing densities, significant variations of temperature, modification of the normal values of such biochemical parameters being frequently considered in the diagnosis of such states (PETERS et al., 1981; PRICOPE et al., 1990; MISÃILÃ, 1998). Lowering of the values of hepatic and muscular glycogen in fish under conditions of stress represents, besides the increase in glycemy, the response given by the organism, which mobilizes all its energetic sources for facing some accidental abnormal situations (DE DOMINIS et al., 1993; REHULKA, 1996).
THE mRNA SECONDARY STRUCTURE’S FOLDING FOR CYPRINUS CARPIO L., 1758 (CYPRINIDAE) INDIVIDUALS CYTOCHROMES’ B GENE HAPLOTYPES FROM MOVILENI AND IASI POPULATIONS
LUCIAN D. GORGAN
Biomolecules exhibit a close interplay between structure and function. Therefore the growing number of RNA molecules with complex functions, beyond that of encoding proteins, has brought increased demand for RNA structure prediction methods. While prediction of tertiary structure is usually infeasible, the area of RNA secondary structures is an example where computational methods have been highly successful. The first practical dynamic programming algorithms to predict the optimal secondary structure of an RNA sequence date back over 20 years (Zuker and Stiegler, 1981). Since then they have been extended to allow prediction of suboptimal structures (Zuker, 1989; Wuchty et al., 1999) and thermodynamic ensembles (McCaskill, 1990), which allow to assign a confidence level or ‘well definedness’ to the predictions (Zuker and Jacobson, 1995). Recently, several methods have addressed the problem of predicting a consensus structure for a group of related RNA sequences (Gorodkin et al, 1997; Hofacker et al., 1998; Luck et al., 1999; Juan and Wilson, 1999; Knudsen, and Hein, 1999; Hofacker et. al., 2002). Such conserved structures are of particular interest, since conservation of structure in spite of sequence variation implies that the structure must be functionally important. By enhancing energy rules with sequence covariation these methods also obtain much better prediction accuracies. Using genetic and molecular phylogeny techniques like PCR, up to sequencing the cytochrome’s b synthesizing gene, for different individuals of Cyprinus carpio L, 1758, sampled from two different populations, we were able to point out the existent differences between those analyzed individuals. All noted differences by comparing individuals from each population, as well as individuals having the origin in different populations, allowed the establishment of the general haplotype for the two studied populations as well as the characteristic haplotype for each population. Towards pointing out the existing differences at the molecular level between individuals of the same species we followed the mRNA’s folding and it’s secondary space structure.
LOW-FREQUENCY LOW INTENSITY MAGNETIC FIELD (50 Hz; 2.7 mT) INFLUENCES AND D2-DOPAMINE RECEPTOR BLOCKADE ON IMMUNE RESPONSE OF THE RAT
CĂLIN MANIU, LUCIAN HRIŢCU, DANA HOROŞANU, CRISTIAN SORIN CÎMPEANU
With the increased urbanization and the fact that electrical appliances are commonly used in our daily life, human beings and many other living organisms as well, are inevitably subject to the frequent exposure to low-frequency electromagnetic fields (EMFs) (Li and Chow, 2001). EMFs range from cosmic rays to the static magnetic fields of earth. Between these extremes is visible light, separating the whole range into ionizing and non-ionizing radiations (Jahn, 2000). Magnetic field intensity is measured in international units called Tesla (T) or in the American units called Gauss (G). One unit Tesla equals 104 Gauss (Repacholi and Greenbaum, 1999). Biological effects of low-frequency fields have been studied during the last three decades. Unfortunately, results of epidemiological studies in this research area have been contentious; results indicated that there is a link between the prevalence of adverse biologic effects and low-frequency field’s exposure, but there is not a significant association between insult and exposure (Anonymous, 1999; Orbach-Arbouys et al., 1999; Caplan et al., 2000). Both low- and high-intensity low frequency fields were subject to extensive investigations in an attempt to settle risk-assessment guidelines for the human exposure. Though residential exposure to low-frequency EMFs such as those from high-voltage powerlines results in low-intensity fields, possibility of human exposure to high-intensity fields has been increased lately due to the increased extent of modernisation. Actually, some electric devices such as the magnetic resonance image (Schenck, 2000) could induce fields that may reach more than 1000-fold the intensity of the residential levels of EMFs. Further, human beings could be exposed to high intensity magnetic fields that may reach thousands Gauss from some magnetic belts and magnetic pads, as well as steel-belted radial tires (Milham et al., 1999).
ASPECTS CONCERNING THE INFLUENCE OF HORMONAL FACTORS OVER THE “IN VITRO” REGENERATIVE PROCESSES AT PEPPER (CAPSICUM ANUUM L.)
TINA OANA CRISTEA, MARIA PRISECARU, SILVICA AMBĂRUŞ
In Romania, the pepper crops (Capsicum annuum L.) occupies an important place in agriculture. The surface occupied with this crops in 2004 was of almost 18.104 ha and the production harvested for fresh consumption was 237.240 Mt (FAO, 2005). Unfortunatelly, this important crop is affected by many pathogens (including viruses, fungi, bacteria and nematodes). But, the most damages are the viruses that may destroy the entire harvest. Therefore, an important goal for pepper breeding is the development or selection of new varieties that shows resistance potentialities. The biotechnology can help the breeding techniques by: obtaining transgenic disease – resistant pepper cultivars, inducing mutations “in vitro” , obtainig virus-free plants using the in vitro specific methods etc. Any of these methods requires an efficient regeneration “in vitro” method which should allow the rapid and fidel multiplication of the valuable selected varieties. Until now was reported: organogenesis from many explants (Agrawal eat al., 1989, Szasz et al., 1995), somatic embryogenesis from anther and immature zygotic embryos (Binzel et al., 1996) and even GMO (through Agrobacterium tumefaciens) – Kang et al., 1998. But until now there were no reports concerning the regeneration protocols for plant regeneration to Romanian pepper genotypes. In our study the main goal was to determine the influence of the hormons over the regeneration of “in vitro” pepper plants.
ASPECTS OF IN VITRO CULTIVATION OF SOME SHRUBS SPECIES
SMARANDA VÂNTU
In vitro cultivation of any species is an unconventional alternative to conserve and perpetuate the genetical resources. It were cultivated Hippophae rhamnoides L. (1), (5), (8), (9), Rubus caesius L (4), (6), and Paliurus spina-christi Mill. (2), (3), (7) and tested their proliferative and regenerative capacity, depended on explants origin, type and concentration of the growth regulators from the culture media.
ENZYMATIC ACTIVITIES FOR THE CRIªUL ALB RIVER SEDIMENTS
MARIOARA NICOLETA FILIMON, MIHAI DRĂGAN-BULARDA
The activity of many enzymes from the soil, or sediments, is a composition of the varied intracellular and extracellular enzymatic components which are produced by microorganisms (bacteria, fungi) or derivatives from the animal and vegetal sources (rests from plants). The enzymatic activities from the soil or sediments are controlled by enzymes included in 4 classes: hidrolase, oxidoreductase, transferase and liase. Urease catalyses the reactions both inside and outside of the organisms that synthesize them, some proteinases can function only outside the cells because of their large size of their substratum and other enzymes such as dehidrogenase ones with some implications in important aspect of the metabolism can function only intracellular (Gianfreda and co., 1996). The sediments are a key link in the biochemical cycle of the elements from the aquatic ecosystem. The organic substances are mineralized here, the ones which were not degraded in water (Muntean and co., 2001). We made a lot of research on the quantitative and qualitative enzymatic activities in the aquatic sediments in the Mureº river (Muntean and all, 2004), in the lakes Ursu and Negru (Muntean and co., 1999), Bazna and Blaj (Drãgan-Bularda and co., 2000), Gilãu (Lumperdeanu and Drãgan-Bularda, 2002).
ACTUAL AND POTENTIAL DEHYDROGENASE ACTIVITIES IN A BROWN LUVIC SOIL
ALINA SAMUEL, SIMONA VICAŞ
It is well know that the dehydrogenase activities are considered as indicators of the global and respiratory activity of soil. In order to obtain new data on the soil enzymological effects of soil management practices we have determined actual and potential dehydrogenase activities in a brown luvic soil submitted to a complex tillage, crop rotation and fertilisation experiment at the Agricultural and Animal Breeding Experiment Station in Oradea (Bihor county). Our results are in good agreement with the literature data reviewed by [1,3,5,7,8] and constitute novelties for the enzymological characterization of a brown luvic soil submitted to a complex management practices.
THE PRESERVATION OF SOME VALUABLE GENOTYPES OF BRASSICA –WHITE CABBAGE - BY “IN VITRO” MICROCLONATION
MARIA PRISECARU, TINA OANA CRISTEA, GHICĂ MIHU
In order to obtain commercial hybrids to this species strictly cross-pollinated plant, it is highly important to maintain the parental lines used in hybrid combinations. In the overcoming of the difficulties raised by the conservation of the vegetal material, specialists appeal most often to “in vitro” cell and vegetable tissue cultures. This technology allows the regeneration of a large number of plants, independently of season, in controlled conditions. The maintenance of such “in vitro” cultures is not expensive and the vegetal material thus obtained is authentic, homogeneous, healthy, high quality and productivity (efficiency) avoiding the phytosanitary risks and the early biological cycles. (1, 2, 3, 6) In our experiment, we obtained the recovery and the maintenance of some parental lines practically lost, starting from some seeds without germinal capacity in normal sowing conditions.