Polymeric nanoparticles - targeted drug delivery systems for treatment of CNS disorders and their possible endocrine disrupting activities.

Drug delivery to the central nervous system (CNS) represents one of the most priority challenges in research and development of pharmaceutical nanotechnology products. Among the various non-invasive approaches for CNS delivery, nanoparticle carriers and particularly polymeric nanoparticles (PNs) seem to be one of the most interesting. This review deals with PNs as CNS drug delivery systems and their potential endocrine disrupting properties. Possible interference with the development of neuroendocrine-reproductive system is considered. Special regard is being paid to potential mechanisms of PNs toxicity. Necessity to investigate the toxicity of nanomaterials and their impact on human health are discussed.

Decontamination by anaerobic stabilisation of the environment contaminated with enteronematode eggs Toxocara canis and Ascaris suum.

Investigations were carried out under operating conditions of Field Composting Factory in Brezno (Slovak Republic) to determine the effect of anaerobic stabilization of organic wastes from public areas on the survival of model helminth Toxocara canis and Ascaris suum eggs. Due to anaerobic conditions, low temperature, low C:N ratio and changes in physical and chemical properties of organic waste, less than 64% of A. suum eggs remained viable after 150 days of stabilisation. The anaerobic stabilisation had a greater effect on the viability of T. canis eggs than on A. suum eggs. The infectivity of T. canis eggs was confirmed by a follow-up experiment in laboratory mice. A small number of T. canis larvae were found in their brain and muscles on day 28 after infection. The results refer to the risks of dissemination, survival and potential spread of endoparasitic developmental stages in the environment through organic wastes subjected to low temperature stabilisation.

HUman MicroNucleus project: international database comparison for results with the cytokinesis-block micronucleus assay in human lymphocytes: I. Effect of laboratory protocol, scoring criteria, and host factors on the frequency of micronuclei.

Micronucleus (MN) expression in peripheral blood lymphocytes is well established as a standard method for monitoring chromosome damage in human populations. The first results of an analysis of pooled data from laboratories using the cytokinesis-block micronucleus (CBMN) assay and participating in the HUMN (HUman MicroNucleus project) international collaborative study are presented. The effects of laboratory protocol, scoring criteria, and host factors on baseline micronucleated binucleate cell (MNC) frequency are evaluated, and a reference range of "normal" values against which future studies may be compared is provided. Primary data from historical records were submitted by 25 laboratories distributed in 16 countries. This resulted in a database of nearly 7000 subjects. Potentially significant differences were present in the methods used by participating laboratories, such as in the type of culture medium, the concentration of cytochalasin-B, the percentage of fetal calf serum, and in the culture method. Differences in criteria for scoring micronuclei were also evident. The overall median MNC frequency in nonexposed (i.e., normal) subjects was 6.5 per thousand and the interquartile range was between 3 and 12 per thousand. An increase in MNC frequency with age was evident in all but two laboratories. The effect of gender, although not so evident in all databases, was also present, with females having a 19% higher level of MNC frequency (95% confidence interval: 14-24%). Statistical analyses were performed using random-effects models for correlated data. Our best model, which included exposure to genotoxic factors, host factors, methods, and scoring criteria, explained 75% of the total variance, with the largest contribution attributable to laboratory methods.

Reduction of 1-methyl-1-nitrosourea-induced mammary gland carcinoma by in vivo application of immunostimulatory CpG motifs in Sprague-Dawley rats.

In the present work the role of 13-cis retinoic acid and CpG oligodeoxynucleotides (CpG-ODN) in a 1-methyl-1-nitrosourea (MNU)-induced mammary gland carcinoma animal model was investigated. Treatment with both components, applied either alone or in combination, induced a significant decrease of the tumour burden and the volume of tumours only in rats that received CpG-ODN (p = 0.046, compared to the MNU control group). The data indicate that the Th-1 biased immunostimulatory capacities of CpG motifs may play a significant role in induction of protective immune responses against mammary gland tumours in Sprague-Dawley rats.

Carotid intima-media thickness in relation to macrovascular disease in patients with type 2 diabetes mellitus.

BACKGROUND: Increased carotid intima-media thickness is regarded as a marker of atherosclerosis. Type 2 diabetes mellitus is associated with a high prevalence of macrovascular disease. MAIN PURPOSE: The present study aimed to examine the relationship between carotid intima-media thickness and the presence of macrovascular disease in patients with type 2 diabetes. METHODS: 71 patients with type 2 diabetes mellitus were studied. The distal common carotid artery and carotid bifurcation intima-media thickness were measured bilaterally with high-resolution ultrasonography. The relationship between the presence of coronary artery disease, cerebrovascular disease and peripheral arterial disease and carotid intima-media thickness was evaluated. RESULTS: Patients with coronary artery disease had significantly (p = 0.048) increased intima-media thickness of the distal common carotid artery. This difference ceased to be significant after adjustment for cardiovascular risk factors. Patients with peripheral arterial disease had a significantly higher bifurcation (p < 0.0001), distal common carotid (p = 0.03) and mean intima-media thickness (p = 0.0008) than did those without peripheral arterial disease. This difference remained significant even after adjustment for other cardiovascular risk factors. In the multiple linear regression analysis, the presence of peripheral arterial disease, age and male gender significantly predicted bifurcation intima-media thickness, while age and the presence of peripheral arterial disease significantly predicted mean intima-medial thickness. CONCLUSIONS: In the present study, the increased carotid intima-media thickness in patients with type 2 diabetes mellitus was related to the presence of peripheral arterial disease. This finding probably reflects morphologic and hemodynamic similarities between the two vascular beds and indicates that increased carotid intima-media thickness in patients with type 2 diabetes may be a marker of atherosclerosis in different locations.

Cytotoxic and genotoxic effect of inhibitor of vulcanisation N-cyclohexylthiophthalimide in a battery of in vitro assays.

Mutagenicity of N-cyclohexylthiophthalimide (Duslin P) was tested first by the Ames test in the bacteria, Salmonella typhimurium. The negative results of the Ames test suggested that this compound does not induce mutations in the genome of S. typhimurium under the conditions used. To estimate the cytotoxicity of Duslin P to human cells, we measured cellular DNA and protein as well as cell proliferation, i.e., the mitotic index of treated and control cells. The genotoxic effects were assayed by two biochemical methods developed for detection of single-strand breaks of DNA in mammalian cells, i.e., by the alkaline single cell gel electrophoresis (comet assay) and by the DNA unwinding method, respectively. The DNA unwinding method showed that this compound did not induce DNA damage at concentrations < 7 micrograms/ml. Alkaline single cell gel electrophoresis revealed approximately double the level of DNA damage (in comparison to untreated control DNA) at a concentration of 2 micrograms/ml, which reduced proliferation to approximately 30%, and triple the level of DNA damage at higher concentrations (6 and 7 micrograms/ml), which inhibited completely both DNA synthesis and proteosynthesis. Cells with moderately damaged DNA were more common than cells with heavily damaged DNA. Parallel experiments with the strong mutagen and carcinogen MNNG showed that MNNG induced in cells a high level of DNA damage at concentrations which did not reduce the mitotic index or proteosynthesis, while DNA synthesis inhibited only partially. After treatment with MNNG, cells with heavily damaged DNA were more common than cells with moderately damaged DNA. Duslin P-treated VH10 cells were also tested cytogenetically, confirming that Duslin P induced neither chromosomal aberrations nor aneuploidy. We conclude that Duslin P has no mutagenic effect on bacteria, does not induce chromosomal aberrations and CREST positive or CREST negative micronuclei in human cells and induces only a small increase of DNA damage in human cells which is consistent with DNA fragmentation due to cell death.

Biomonitoring of genotoxic risk in workers in a rubber factory: comparison of the Comet assay with cytogenetic methods and immunology.

Several substances used in rubber processing are known to be genotoxic. Workers in a rubber tyre factory, exposed to a broad spectrum of contaminants such as benzo[a]pyrene, benzo-fluoranthene, naphthalene, acetonaphthene, alkenes and 1,3-butadiene have been regularly examined for several years: chromosomal aberrations in lymphocytes, mutagenicity of urine (by use of the Ames test) and various parameters of blood and urine were assessed. An elevated level of mercapturic acid derivatives was found in the urine of employees, which is indicative of environmental exposure to toxicants with alkylating activity. We have now extended this study by examining genotoxicity with the modified Comet assay in parallel with chromosomal aberrations and micronucleus formation as well as immunological endpoints. Twenty-nine exposed workers from this factory were compared with 22 non-exposed administrative staff working in the same factory, as well as with 22 laboratory workers. The absolute numbers of peripheral leukocytes were significantly higher in the exposed group than in either of the control groups (p < 0.001). The erythrocyte mean cell volume was significantly higher in exposed workers in comparison with laboratory controls (p < 0.05). Percentages of lymphocytes, polymorphonuclear leukocytes, monocytes and eosinophils were not altered. The proliferative response of T- and B-cells to mitogen treatment when calculated per number of lymphocytes and adjusted for smoking, age and years of exposure did not differ between exposed and control groups. Endogenous strand breaks (including alkali-labile sites) and altered bases (formamidopyrimidine glycosylase- and endonuclease III-sensitive sites) were measured by the Comet assay in lymphocyte DNA. Exposed workers had significantly elevated levels of DNA breaks compared with office workers (p < 0.00001) or with laboratory controls (p < 0.00001). Micronuclei occurred at significantly higher frequencies in the exposed group than in controls (p < 0.00001), though the frequencies were all within the normal range. Significant correlations were seen between individual values of strand breaks, micronuclei and chromatid/chromosome breaks and certain immunological parameters.

Bacterial proteases: production, isolation and utilization in animal nutrition.

Under conditions of submerged fermentation of Bacillus licheniformis strain L-3 in 15-L MBR-Schulzer bioreactor, the maximum production of proteolytic enzymes was achieved in the nutrient medium which contained 1% milk powder, 0.3% yeast autolysate, 0.5% corn starch and malt (20 ml per 100 ml of the medium). The preparation obtained of extracellular alkaline bacterial Ser-protease of the subtilisin type is characterized by optimum pH 9.8-10.2 good up to a temperature stability (65 degrees C) and has molecular weight cca of 26 kDa. The use of chemical mutagens (HNO2, 5-bromouracil) has enabled to select new strains (L-3N and L-3U) whose protease activity is 1.8-2.2 times higher as compared to the original Bacillus licheniformis strain L-3. The addition of these enzymes to the fodder has a positive effect on the retention of nitrogen substances.

[Diagnosis of chronic massive pulmonary thromboembolism in elderly patients]. / Diagnostika chronickej masívnej tromboembólie pl'úcnice u chorých v starsom veku.

Chronic massive thromboembolism of the pulmonary artery is an occlusion of the major branches of the pulmonary artery which develops as a result of repeated embolisms, as a result of non-dissolution and organizing of a thrombus or retrograde growth of a thrombus. The authors observed four elderly patients with chronic massive pulmonary embolization. In their clinical picture dominated progressing dyspnoea and signs of right heart failure. In the diagnosis perfusion scan of the lungs and pulmoangiographic examination plays an important part as they revealed even unilateral absence of pulmonary circulation. This examination was stimulated by weaker respiration at the site of the lacking perfusion in a portion of the lungs.

Comparison of the in vitro effect of adriblastina on induction of SCEs in V79 cells and human peripheral blood lymphocytes.

Induction of sister chromatid exchanges (SCEs) by the cytotoxic antibiotic adriblastina (doxorubicin, 14-hydroxyrubidomycin) of the anthracycline group isolated from Streptomyces peucetius var. caesius by Farmitalia Research Laboratories was tested in vitro at concentrations of 0.01 microgram/ml, 0.1 microgram/ml and 0.2 microgram/ml using V79 cells and human peripheral blood lymphocytes from healthy donors. In comparison with negative control, adriblastina significantly elevated the SCE frequency both in V79 cells and in human peripheral blood lymphocytes. The results obtained by comparing the effect of equivalent adriblastina concentrations on V79 cells and human peripheral blood lymphocytes showed no significant difference in the mutagenicity effect of both of these cell lines to adriblastina.

Assessment of toxicity, clastogenicity, mutagenicity and transforming activity of pentoxifylline in mammalian cells cultured in vitro.

We tested the possible cytotoxic, clastogenic and genotoxic effects of pentoxifylline on different lines of mammalian cells cultured in vitro. This study was part of the developmental research of agapurin, since pentoxifylline represents an effective compound of this drug. Cells treated for a short time manifested a relatively high resistance to the toxic effects of pentoxifylline. Generally, only cells treated for a long time (18 h) or a short time (2 h) with high concentrations of drug manifested sensitivity to the toxic effects of pentoxifylline. Although the tested drug induced DNA synthesis inhibition in V79 and EUE cells and clastogenic effects in V79 cells, it was not able to induce either 6-TGr mutations in the HGPRT locus of V79 cells or morphological transformation of Syrian hamster embryo cells. Adding of microsomal fraction S9 to the treated cells did not markedly change the effects of pentoxifylline on different studied endpoints. We suggest that pentoxifylline has no genotoxic effects, and that the cytotoxicity and induction of chromosomal aberrations were induced by inhibition of cellular DNA replication.

[Comparative study of the protective effects of 3 carboxylic acids on urea and ammonia toxicity in sheep]. / Porovnávacie stúdium protektívneho úcinku troch karboxylových kyselín na toxicitu cpavku a mocoviny pri ovciach.

Three carboxylic acids (acetic, propionic and citric) were compared as to their protective effect in controlling the toxic and lethal action of urea in sheep. It was derived from the metabolic and clinical studies that citric acid was the most effective of all the acids studied and can be used in the preventive treatment of sheep against the toxic lethal action of urea and ammonia. The mechanism of the action of citric acid is also discussed in relation with other findings.