Search NEL Online

Comparative Study 2006; 27(Suppl 2): 96-99 PubMed PMID: 17159789 Citation  Keywords:  Animals, Drug Compounding, Female, Magnetics, Metal Nanoparticles:analysis, Mice, Mice, Inbred ICR, Polyesters:chemistry, Toxicity Tests,.   

OBJECTIVES: The acute toxicity of magnetic nanoparticles was effectively lowered by their encapsulation with poly(D,L lactide). In relation to the idea to use magnetic nanoparticles in development of new delivery systems suitable for targeted drug administration, the toxicological profile of five types of magnetic fluids was assessed in mice.

METHODS: The nanoprecipitation method was used to prepare magnetic fluids containing nanoparticles of Fe(3)O(4) encapsulated with biodegradable substances. The acute toxicity testing was performed according to OECD Test Guideline 425. In the pilot distribution study a special staining method was examined for the detection of Fe ions in body tissues of mice after intravenous administration of magnetic fluids.

RESULTS: The p.o. LD(50) values were greater than 2,000.0 mg/kg of body weight and i.v. LD(50) values were in the range of 231.7-558.9 mg/kg of body weight.

CONCLUSIONS: Of the magnetic nanoparticles tested, those encapsulated with poly(D,L lactide) were the most prospective for further in vivo testing....

Read abstract

Comparative Study 2006; 27(Suppl 2): 91-95 PubMed PMID: 17159788 Citation  Keywords:  Alkaline Phosphatase:blood, Animals, Blood Cell Count, Blood Cells:drug effects, Butyrylcholinesterase:metabolism, Carps:anatomy & histology, Creatine Kinase:blood, Hyperplasia:chemically induced, Insecticides:toxicity, Lactic Acid:blood, Pancreas:patholo.   

OBJECTIVES: The study aimed at assessing the effects of a pyrethroid cypermethrin on common carp (Cyprinus carpio L.) on the basis of the results of acute toxicity tests and haematological, biochemical and histological examinations.

METHODS: Experimental carp were exposed to the pesticide preparation Alimetrin 10 EM in the concentration of 29.1 microg/l(-1) (96hLC(50)) corresponding to 29.1 microg/l(-1) of cypermethrin in a 96 h acute toxicity test. The results of the test and of the examinations of exposed carp were compared with the results of carp from the control group.

RESULTS: In haematological profile, the experimental group of carp showed a significant (P<0.01) increase in the number of erythrocytes, segmented neutrophile granulocytes, developmental forms of myeloid sequence and eosinophiles, and a significant (P<0.01) decrease in mean erythrocyte volume, mean erythrocyte haemoglobin and lymphocyte count. As far as biochemical indices are concerned, the exposure caused a significant (P<0.01) increase in glucose and lactate concentration and creatine kinase activity, and a significant (P<0.01) decrease in total proteins, albumins, total globulins, ammonia, lactate dehydrogenase and alkaline phosphatase in blood plasma of exposed carp compared to the control group. Histopathological tissue examinations proved random hyperaemia and perivascular lymphocyte infiltration in skin, respiratory epithelium hyperplasia and chloride cell activation in gills, and pancreas exocrine cell vacuolisation in common carp after the exposure.

CONCLUSIONS: The exposure of common carp to 29.1 microg/l(-1) of Alimetrin 10 EM caused significant shifts in haematological and biochemical profile and histopathological changes in organ tissues. The cypermethrin-based pesticide Alimetrin 10 EM was classified among substances strongly toxic for fish....

Read abstract

Comparative Study 2006; 27(Suppl 2): 86-90 PubMed PMID: 17159787 Citation  Keywords:  Adult, Bystander Effect:radiation effects, Carcinoma:etiology, Computer Simulation, Humans, Lung:radiation effects, Lung Neoplasms:etiology, Models, Biological, Neoplasms, Radiation-Induced, Radon Daughters:toxicity, Risk Factors, Smoking:adverse effects,.   

OBJECTIVES: Exposure to radon and radon decay products represents one of the greatest risks of ionizing radiation from natural sources in some residential and working areas. Recently increasing attention has been paid to accurate estimations of this health risk by using various models.

METHODS: In the presented study, a bystander model was used to predict biological effects of radon products on lung tissue target cells. The model considers radiation response as a superposition of the direct alpha particles hit effect and the bystander (cells communication) effect. Energy deposition in the lung tissue and in the air gap was calculated using the Bethe-Bloch equation. The exponential distribution of radon progenies in the mucous layer of smokers and non-smokers was evaluated.

RESULTS: The excess relative risk value of lung cancer occurrence per unit exposure obtained in our study was ERR/WLM=0.0047 for smokers and ERR/WLM=0.0171 (taking into account the environment in radioactive ore mines) for non-smokers. Other published results give the average excess relative risk values per unit exposure in the dwellings for smokers ERR=0.050 per 100 Bq.m(-3) and for non-smokers ERR=0.198 per 100 B.qm(-3). Results presented in this study are in good agreement with the published epidemiological data on lung cancer incidence for mines and residential areas.

CONCLUSIONS: The bystander model is suitable for radon risk prediction in dwellings and at workplaces (residential and working areas)....

Read abstract

Evaluation Studies 2006; 27(Suppl 2): 82-85 PubMed PMID: 17159786 Citation  Keywords:  Animals, Animals, Newborn, Antioxidants:therapeutic use, Behavior, Animal:drug effects, Carbolines:therapeutic use, Female, Growth and Development:drug effects, Hypoxia:pathology, Male, Motor Activity:drug effects, Pregnancy, Pregnancy, Animal, Premedicat.   

OBJECTIVES: The aim of this study was to evaluate the effect of the synthetic pyridoindole antioxidant stobadine (STO, 50mg/kg/day) on behavioural alterations induced by acute neonatal anoxia in rat offspring.

METHODS: STO was administered orally from day 15 of gestation up to day 7 post partum (PP). Pups of both genders were exposed to anoxia (100% N(2) for 10 minutes in a special glass chamber) on day 6 PP. After the anoxic insult, neurobehavioural development of rats (somatic growth and maturation, neuromotor and reflex development, spontaneous behaviour in open field) was evaluated up to adulthood.

RESULTS: Neonatal anoxia did not affect somatic growth and maturation. The anoxic insult resulted in hyperactivity of male offspring in the open field test. STO pretreatment was found to decrease the anoxia induced hyperactivity in male offspring, and affected also the performance of pups on rotating rod.

CONCLUSIONS: Since STO reduced anoxia-induced hyperactivity, we suggest its potential protective effect in acute hypoxic insults in the perinatal period....

Read abstract

Journal Article 2006; 27(Suppl 2): 78-81 PubMed PMID: 17159785 Citation  Keywords:  Acetylglucosaminidase:analysis, Animals, Animals, Newborn, Biomarkers:analysis, Brain Chemistry, Disease Models, Animal, Female, Glutathione:analysis, Hypoxia:metabolism, Lactic Acid:analysis, Liver:chemistry, Lung:chemistry, Rats, Rats, Wistar,.   

OBJECTIVES: To assess the time course of biochemical responses to neonatal anoxia.

METHODS: Neonatal anoxia was induced by placing 2-day-old rat pups into a glass chamber with 100% N(2) atmosphere, T=36.5 degrees C, for 20 minutes. The samples of serum, brain, lungs and liver were taken after 10 minutes, 2, 6, 12, 24 and 48 hours following the insult. The biochemical profile consisted of measurements of lactate, glutathione and the lysosomal enzyme N-acetyl-beta-D-glucosaminidase.

RESULTS: Ten minutes after the insult, neonatal anoxia caused a threefold increase of the lactate level in serum as well as in all organs assessed, returning to control values in 2 hours. The profile of glutathione in the liver showed a time-dependent rise observed in both groups. No significant changes were seen in N-acetyl-beta-D-glucosaminidase response.

CONCLUSIONS: The results indicate disruption of aerobic metabolism in our experimental model of neonatal anoxia, as proved by sharply increasing lactate levels. The rising glutathione level in the liver suggests improving antioxidant competences of the developing organism. Although the model used requires further specification, the obtained data are indicative of its usefulness in the study of neonatal anoxia....

Read abstract

Evaluation Studies 2006; 27(Suppl 2): 69-73 PubMed PMID: 17159783 Citation  Keywords:  Animals, Animals, Newborn, Dietary Supplements, Female, Fetal Hypoxia:chemically induced, Fetal Viability:drug effects, Growth and Development:drug effects, Male, Phenytoin:toxicity, Pregnancy, Pregnancy, Animal, Prenatal Exposure Delayed Effects:preventi.   

OBJECTIVES: The aim of this study was to test the effect of supranutritional dosage of the natural antioxidant vitamin E (VitE) on phenytoin (PHT) induced developmental toxicity and possible long-term effects in rat offspring.

METHODS: PHT (150 mg/kg) was administered by oral gavage daily from day 7 to 18 of gestation and VitE prior to PHT orally on the same days.

RESULTS: PHT administration alone resulted in decreased survival rate and lower body weight of pups on day 21 post partum (PP). Moreover, PHT slightly changed somatic growth and pups failed to present dynamic air righting on days 15-20 PP. VitE supplementation did not alleviate these changes but rather induced persisting body weight reduction on the days 21 PP and 100 PP. We observed also decreased brain wet weight in the PHT and VitE + PHT groups compared to controls.

CONCLUSIONS: We concluded that prenatal supplementation with 500 mg/kg of VitE did not ameliorate the developmental toxicity of PHT and failed to protect postnatal development of rat offspring. Further, in the group supplemented with VitE, the occurrence of persistent body weight gain depression up to adulthood indicates its possible interference with somatic growth regulation....

Read abstract

Comparative Study 2006; 27(Suppl 2): 65-68 PubMed PMID: 17159782 Citation  Keywords:  Asphyxia Neonatorum:blood, Delivery, Obstetric, Glutathione Peroxidase:blood, Humans, Infant, Newborn, Malondialdehyde:blood, Oxidative Stress, Stress, Physiological:blood, Superoxide Dismutase:blood, Term Birth:blood,.   

OBJECTIVES: In healthy term newborns (HTN) to determine on the 1st and 5th day of life the activity of total antioxidant capacity (TAS), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX) and to compare the values with the group of asphyxiated term newborns (ATN).

PATIENTS/METHODS: The series consisted of 15 HTN and 24 ATN. In both groups TAS, MDA, GPX and SOD were investigated.

RESULTS: Reference values in HTN (1st/5th day of life) for TAS were 0.52+/-0.03/0.49+/-0.04 mmol/l, for MDA 0.72+/-0.07/1.08+/-0.09 micromol/l, for SOD 594.20+/-16.47/591.23+/-14.14 Ug/Hb and for GPX 25.48+/-1.32/25.98+/-1.20 Ug/Hb. In a group of ATN the obtained values were (1st/5th day of life): TAS 1.1+/-0.08/0.98+/-0.08 mmol/l, MDA 2.08+/-0.22/2.21+/-0.34 micromol/l, SOD 509.18+/-26.8/564.49+/-36.4 Ug/Hb and GPX 30.2+/-1.9/32.45+/-2.69 Ug/Hb.

CONCLUSIONS: Statistically significant differences were found on the 1st and 5th day of life between the two groups investigated in values of MDA (**p<0.01) and TAS (**p<0.01). Increased values of MDA in the group of ATN on the 1st and 5th day of life confirmed the presence of lipoperoxidation. The obtained values of TAS on the 1st and 5th day of life in the group of ATN were surprisingly higher than in HTN. The increase of TAS in ATN could point to a certain ability of ATN to prevent the damage of balance between overproduction of MDA and antioxidants. The results of SOD and GPX activity were not statistically significant, yet they are indicative of the biochemical reaction of the organism of term newborns to asphyxia....

Read abstract

Journal Article 2006; 27(Suppl 2): 57-60 PubMed PMID: 17159780 Citation  Keywords:  Adult, Antineoplastic Agents:toxicity, Chromosomes, Human, DNA Damage, DNA-Binding Proteins:genetics, Female, Gene Frequency, Genetic Predisposition to Disease, Humans, Male, Medical Staff, Hospital, Middle Aged, Occupational Diseases:chemically induced, .   

OBJECTIVES: Medical workers in oncological units have chronically been exposed to low doses of cytostatics (C) with potential consequences on DNA and chromosomal integrity. Our study addresses relationships between chromosomal aberrations (CAs), chromosome (CSA), and chromatid (CTA) types and polymorphisms in DNA repair genes XRCC1 and XRCC3.

METHODS: The study was conducted on 72 exposed individuals from hospitals in Martin (HMT; 28 individuals), Ruzomberok (HRK; 31 medical workers) and in Trstená (HTS; 13 individuals), and on 34 unexposed individuals. Conventional cytogenetic analysis was employed for the detection of CAs. XRCC1 and XRCC3 polymorphisms were assayed for by Taqman SNP genotyping assays ("Assay-by-Demand") using Real-Time allelic discrimination on AB 7 500 equipment (all from Applied Biosystems, Foster City, USA).

RESULTS: Higher frequencies of CAs were detected in exposed individuals than in controls (1.78% versus 1.32%, respectively). The frequency of aberrant cells (Ab.c.) was highest among workers from HRK (1.97%), followed by those from HMT and HTS (1.54% and 1.85 %, respectively). In the exposed group a moderately higher frequency of CTA (0.93%) in comparison with CSA (0.85%) was detected. Higher CAs were detected in individuals with homozygous variant polymorphism in XRCC1 exon 10 gene than in those with wild-type genotype (1.87% versus 1.60%). Variant T allele in XRCC3 exon 7 was also associated with higher CAs (1.71% and 1.74%) as compared to the wild-type C allele (1.45%).

CONCLUSIONS: The detection of individuals with increased susceptibility to genotoxic agents enables to take preventive measures during the working process....

Read abstract