The effect of arsenic, cadmium, mercury, and lead on the genotoxic activity of Boletaceae family mushrooms present in Serbia.

The aim of this study was to determine accumulation of heavy metals and metalloids which are widely distributed in the environment and in food chain using wild edible mushrooms belonging to the Boletaceae family mushrooms. In addition, methanol extracts of mushrooms were tested for in vitro protective effect by the cytochalasin-B blocked micronucleus (CBMN) assay using chromosome aberrations in human peripheral lymphocytes as a model. The genotoxic activity of methanol extracts prepared at 4 different concentrations (1, 2, 3 or 6 µg/ml) was examined using amifostine and mitomycin C as positive controls. Extracts of species B. regius and B. edulis exhibited the greatest reduction in the frequency of micronuclei (MN). Extract of B. regius at concentrations of 2 µg/ml showed the highest decrease in number of MN. In comparison, extract of mushroom B. edulis at a concentration of 3 µg/ml displayed less reduction. However, as heavy metals and metalloids are found in mushrooms, another aim was to examine whether these agents affected genotoxicity. Principal component analysis (PCA) identified clustering differences between control and heavy metals and metalloids groups and might explain the influence of heavy element content and genotoxic activity in mushrooms.

The effect of the octenidine-based oral antiseptic on the structure of microbial communities and periodontal status in patients with fixed orthodontic treatments.

OBJECTIVE: To evaluate the effect of an octenidine (OCT)-based antiseptic on the gingival inflammation and microbial composition of subgingival dental plaque in patients with fixed orthodontic appliances. PATIENTS AND METHODS: Thirty-three orthodontic patients were randomized into 2 groups. The control group patients were given standard oral hygiene and dietary advice, while the experimental group patients used an OCT-based antiseptic together with standard oral hygiene and dietary recommendations. The periodontal status was evaluated using the following indices: the plaque index (PI), the gingival index (GI), the papilla bleeding index (PBI) and the probing pocket depth (PD). Next Generation Sequencing of the 16S rRNA amplicons was performed in order to assess the subgingival microbiome. RESULTS: The PD values obtained were significantly lower in the experimental group after one month, as well as PBI. The microbiological analysis showed a significant increase in the occurrence of the genus Prevotella in the control group, while the number of other periodontopathogens remained stable in both groups. The changes in the abundance of the bacteria not directly associated with periodontal disease were also observed. CONCLUSIONS: The use of an OCT-based antiseptic has a positive effect on the prevention of gingival inflammation. Additionally, it also prevents a likely increase in numbers of periodontopathogens of the subgingival dental plaque in the first three months of fixed orthodontic treatment.

Secondary metabolites of Seseli rigidum: Chemical composition plus antioxidant, antimicrobial and cholinesterase inhibition activity.

Extracts of different polarity obtained from various plant parts (root, leaf, flower and fruit) of Seseli rigidum were studied by different antioxidant assays: DPPH and ABTS radical scavenging activity, by total reducing power method as well as via total content of flavonoids and polyphenols. Essential oils of all plant parts showed weak antioxidant characteristics. The inhibitory concentration range of the tested extracts, against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and fungi Candida albicans and Aspergillus niger was 0.01-1.50 mg/mL and of a microbicidal 0.02-3.00 mg/mL. In the interaction with cholinesterase, all essential oils proved effective as inhibitors. The highest percentage of inhibition versus human and horse cholinesterase was shown by root essential oil (38.20% and 48.30%, respectively) among oils, and root hexane extract (40.56% and 50.65% respectively). Essential oils and volatile components of all plant parts were identified by GC, GC-MS and headspace/GC-MS. Statistical analysis of the ensemble of results showed that the root essential oil composition differed significantly from essential oils of other parts of the plant. Taking into account all of the studied activities, the root hexane extract showed the best overall properties. By means of high performance liquid chromatography coupled to high resolution mass spectrometry, the 30 most abundant constituents were identified in extracts of different polarity. The presence of identified constituents was linked to observed specific biological activities, thus designating compounds potentially responsible for each exhibited activity.

Kinetic-photometric determination of iodide based on its inhibitory effect on the bromate oxidation of Victoria Blue 4-R.

A new sensitive kinetic method has been developed for the determination of trace amounts of I- over the range of 50-300 ng cm(-3). The method was based on the inhibitory effect of iodide on the oxidation of Victoria Blue 4-R by KBrO3. The reaction is monitored spectrophotometrically at 596.3 nm. Method development includes optimization of reagent concentration and temperature. The kinetic parameters of the reaction were reported and a rate equation was suggested. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The proposed method was successfully applied to the determination of iodide in real samples. The new developed method was found to have fairly good selectivity, sensitivity, simplicity and rapidity.

[Evaluation of the health status of workers exposed to carbon disulfide]. / Evaluacija zdravstvenog stanja radnika izlozenih ugljen disulfidu.

The investigation included 134 workers from a viscose rayon factory who were exposed to average concentrations of carbon disulphide exceeding MAC values (x = 119.3 mg/m3) for more than 75% of their working hours. Workers' chronic morbidity from carbon disulphide exposure was analysed over a three-year period, and results were compared with those for a control group of the same age but with a shorter exposure duration. The percentage of ill workers and the prevalence rate were both similar to those of the control group. However, as concerns the specific morbidity caused by carbon disulphide exposure, toxic polyneuropathy was present only among the exposed workers. In that group hypertension too reached a higher prevalence rate, statistically significant, although both groups consisted of younger workers of similar age. The prevalence of other diseases was comparable, possibly because of the selection bias, and the healthy worker effect. Owing to that effect workers with the most distinct symptoms had been removed from their jobs and, consequently, excluded from examinations. That could have been a reason for underestimating exposure effects.

Wild fire impact on copper, zinc, lead and cadmium distribution in soil and relation with abundance in selected plants of Lamiaceae family from Vidlic Mountain (Serbia).

Fire has been considered as an improving factor in soil quality, but only if it is controlled. Severe wild fire occurred in the summer 2007 on the Vidlic Mountain (Serbia) overspreading a huge area of meadows and forests. Main soil characteristics and content of heavy metals (Cu, Pb, Cd, Zn) in different fractions obtained after sequential extraction of soil from post-fire areas and from fire non disturbed areas were studied. In four plant species of Lamiaceae family (Ajuga genevensis L., Lamium galeobdolon (L.) L., Teucrium chamaedrys L., Acinos alpinus (L.) Moench.), that grow in typical habitats of the mountain, distribution of heavy metals in aerial parts and roots was investigated too. For all samples from post-fire area cation exchange capacity and soil organic matter content are increased while rH is decreased. Fire caused slightly increased bioavailability of the observed metals but more significant rise happened in metal amounts bound to oxides and organics. The plants showed variable behavior. T. chamaedrys collected on the post-fire area contained elevated concentrations of all analyzed metals. A. alpinus showed higher phytoaccumulation for Zn and Cd, while the other two plant species for Pb and Cd in the post-fire areas.

A modification of the kinetic determination of pancuronium bromide based on its inhibitory effect on cholinesterase.

A modification of the existing spectrophotometric kinetic method for the determination of pancuronium bromide (PCBr), based on pooled human serum cholinesterase (ChE, EC 3.1.1.8 acylcholine acylhydrolase) inhibition, was developed. Butyrylthiocholine iodide (concentration 1.667 mmol/L) was used as substrate and determination was performed at pH 7.6. Essential basic kinetic parameters were also determined: Michaelis-Menten's constant KM=0.33 mmol/L, maximal reaction rate Vmax=42.29 micromol/L min, inhibition constant KI=0.34 micromol/L, and IC50=0.235 micromol/L. Linear dependence between the reaction rate and the inhibitor concentration exists in PCBr concentration range 8.29-265.28 nmol/L, which corresponds to the real sample concentrations from 0.166 to 5.306 micromol/L. The method detection limit was established to be 1.86 nmol/L and the quantification limit was 6.18 nmol/L. Precision of the method was tested for three pancuronium concentrations (16.58, 99.48, and 198.96 nmol/L). The relative standard deviation (RSD) was in the range 0.78-5.13%. Accuracy was examined by the standard addition method. The influence of substances usually present in serum and urine on the reaction rate was determined. The method developed was applied for PCBr determination in spiked serum and urine samples and in the urine taken during surgery. The method was proven to have good sensitivity, accuracy, and precision and can be considered suitable for clinical practice.

[Psychophysiological fatigue in persons with normal and increased blood pressure during work with video display terminals]. / Psihofizioloski zamor kod osoba s normalnim i povisenim krvnim pritiskom pri radu s videoterminalom

In a field study, on the sample of 73 phototype-setters employed in newspaper press, various data of objective and subjective changes in psychophysiological functions were collected during work with Video Display Terminals. Using the "matched pairs" method, two groups were definitely formed; the first with normal blood pressure and the second with increased blood pressure. The subjects of 11 matched pairs within these two groups differed in value of blood pressure measured at the beginning of work, while they were matched with respect to sex, age, shift of work and the level of psychophysiological abilities that were examined at the beginning of work by fatigue tests. In addition to questionaries, the following methods were applied: flicker fusion frequency, dynamometry, reaction time measurement and measurements of retinal adaptation to darkness, convergence, stereoscopic vision and lateral phorias. The higher degree of general psychophysiological fatigue was discovered in group with increased blood pressure, but the same was not true for more specific visual fatigue that was more apparent in group of phototype-setters with normal blood pressure. According to one division of the degree of fatigue based on investigation of 50 different occupations with combined mental and physical work, it can be concluded that the degree of fatigue that was found in the group of phototype-setters with increased blood pressure during work with Video Display Terminals, is relatively the highest, so that it is very difficult for workers to adjust to it in biological sense.