Variability in DNA damage of chub (Squalius cephalus L.) blood, gill and liver cells during the annual cycle.

In this work the genotoxic potential of water in three localities in Serbia, which differ by the nature and degree of pollution, was determined in tissues of European chub (Squalius cephalus L.) on monthly basis over the 2011/2012 year season using the alkaline comet assay. Specimen samples of chub were taken from Special Nature Reserve "Uvac", as control site, and Pestan and Beljanica Rivers, as polluted sites at Kolubara basin, surrounded with coal mines. Three tissues, blood, gills and liver were used for assessing the level of DNA damage. Analysis was done by software (Comet Assay IV). The control site at Reserve "Uvac" showed the lowest DNA damage values for all three tissues compared to Pestan and Beljanica. Blood has the lowest level of DNA damage in comparison with liver and gills. Decreased damage for all three tissues was observed at summer, while during the spring and autumn damage increased.

Comparison of comet assay parameters for estimation of genotoxicity by sum of ranking differences.

The genotoxic potential of waters in six rivers and reservoirs from Serbia was monitored in different tissues of chub (Squalius cephalus L. 1758) with the alkaline comet assay. The comet assay, or single-cell gel electrophoresis, has a wide application as a simple and sensitive method for evaluating DNA damage in fish exposed to various xenobiotics in the aquatic environment. Three types of cells, erythrocytes, gill cells, and liver cells, were used for assessing DNA damage. Images of randomly selected cells were analyzed with a Leica fluorescence microscope and image analysis by software (Comet Assay IV Image analysis system, PI, UK). Three parameters (tail length-l, tail intensity-i, and Olive tail moment-m) were analyzed on 1,700 nuclei per cell type. The procedure for sum of ranking differences (SRD) was implemented to compare different types of cells and different parameters for estimation of DNA damage. Regarding our nine different estimations of genotoxicity: tail length, intensity, and moment in erythrocytes (rel, rei, rem), liver cells (rll, rli, rlm), and gill cells (rgl, rgi, rgm), the SRD procedure has shown that the Olive tail moment and tail intensity are (almost) equally good parameters; the SRD value was lower for the tail moment and tail intensity than for tail length in the case of all types of cells. The least reliable parameter was rel; close to the borderline case were rei, rll, and rgl (~5 % probability of random ranking).

Distribution and accumulation of elements (As, Cu, Fe, Hg, Mn, and Zn) in tissues of fish species from different trophic levels in the Danube River at the confluence with the Sava River (Serbia).

Pikeperch (Sander lucioperca), European catfish (Silurus glanis), common carp (Cyprinus carpio), and gobies (Neogobius gymnotrachelus, Neogobius melanostomus) were collected from the Danube River (Belgrade section), and samples of liver, muscle, or whole-body composites (in the case of gobies) were analyzed for As, Cu, Fe, Hg, Mn, and Zn with inductively coupled plasma optical spectrometry to find out if there was a correlation between accumulation of these elements in predatory and prey species, as well as in pairs of species with overlapping diets. Concentrations of all analyzed elements were either higher (Cu, Fe, Mn, Zn) in liver than in muscle, or equal (As, Hg), except for Hg in carp, which was higher in muscle. Mercury concentration in liver and muscle of predators (catfish, pikeperch) was significantly (<10(-4)) higher than in prey fishes (carp and gobies). The results indicate that Hg concentration was biomagnified through the food chain. Concentrations of As, Fe, and Hg in carp liver and gobies whole-body composite were similar, but carp had significantly (<10(-4)) higher values of Zn and Cu in liver. The regression analysis and trendline equations indicate that the concentrations of all tested elements, except for As in liver, and Mn and Fe in muscle, were similar in predatory fish (pikeperch and catfish), on one hand, and in prey fish (carp and gobies), on the other hand. Distinctly high Zn concentration in carp is very common in this species due to its physiology. Concentrations of Hg and Zn were higher than the maximum acceptable concentration due to the high pollution level in this section of the Danube River, accordingly posing a risk for the human consumption of these fish species.

Sinergasilus polycolpus, a new copepod species in the ichthyoparasitofauna of Serbia and Montenegro.

The parasitic copepod Sinergasilus polycolpus was identified on the gills of bighead carp Aristichthys nobilis from 2 localities (Kladovo and Slankamen) in the Serbian part of the River Danube. This parasite is species-specific for 2 Chinese carp, the bighead carp and the silver carp Hypophthalmichthys molitrix. It was accidentally introduced into Serbia and Montenegro together with fry of these herbivorous carp intended for aquaculture and control of phytoplankton blooms. There is no record in the available literature of this parasite for European freshwaters. Our identification of S. polycolpus signals the possible spread of the infectious disease sinergasilosis in natural freshwaters and in fishponds, similar to bothriocephalosis, caused by Bothriocephalus opsariichthydis, which was introduced with the fry of various herbivorous species from the Amour River basin (USSR) into almost all countries throughout the world.

Long-term inhibition of tinnitus by UltraQuiet therapy: preliminary report.

Masking of tinnitus by noise can produce residual inhibition, a persistence in the reduction in tinnitus after the noise is removed. Typically, this relief is very short-lived, on the order of minutes. This report highlights long-term inhibition of tinnitus by UltraQuiet therapy, a new technique that employs patterned sound in the 10- to 20-kHz range, presented through bone conduction. Nine subjects participated in a study of the efficacy of this tinnitus suppression technique. Eight reported improvement in tinnitus symptoms; one did not complete the study. The duration of the improvement ranged from days to weeks. This long-term inhibition may involve a truly plastic change in the brain at the central level.

Indolocarbazoles exhibit strong antiviral activity against human cytomegalovirus and are potent inhibitors of the pUL97 protein kinase.

We have analyzed a panel of protein kinase inhibitors (PKIs) and found that some indolocarbazoles (Gö6976, K252a, K252c) proved to be highly effective inhibitors of GCV-sensitive and -resistant human cytomegalovirus (HCMV) strains, but did not show any effect against herpes simplex virus. Antiviral activity was determined by focus reduction assays (IC(50) ranging from 0.009 to 0.4 microM). Other inhibitors of serine/threonine kinases (Gö6850, H-7, roscovitine) were found to be ineffective. Virus yield at 5 days after infection was reduced by three orders of magnitude with nanomolar concentrations of the indolocarbazoles. These compounds were fully effective when added up to 24 h post infection and showed reduced activity up to 72 h post infection. Cytotoxicity assays in proliferating and non-proliferating cells demonstrated that the effective antiviral concentration of these compounds was significantly lower than either antiproliferative (IC(50)/CC(50) ranging from 6.5 to 390) or cytotoxic (IC(50)/CC(50) ranging from 72. 5 to 1000) doses. The effects of PKIs on the virus-encoded protein kinase pUL97 were studied using recombinant vaccinia viruses. Indolocarbazoles strongly inhibited both pUL97 autophosphorylation (IC(50) ranging from 0.0012 to 0.013 microM) and pUL97-dependent ganciclovir phosphorylation (IC(50) ranging from 0.05 to 0.26 microM). Other inhibitors of serine/threonine kinases showed only weak (Gö6850) or no (H-7, roscovitine) effect on these pUL97 functions, while oxoflavone tyrosine kinase inhibitors had no effect at all.

[The testing of the toxicity of the plastics used in orthodontics]. / Testung der Toxizität von in der Kieferorthopädie verwendeten Kunststoffen.

Eighteen bracket adhesives and one to three differently coloured samples of the plastic materials Orthocryl and Wil-o-dont used for removable appliances were tested for toxicity in vitro by cell culture using both L-929 mouse fibroblasts and human keratinocytes. The results differed from product to product. Some adhesives were moderately and some slightly toxic, while others were non-toxic. After 30 days of washing in PBS, none of the adhesives showed any toxicity. Orthocryl was not toxic regardless of colour, while the possible toxicity of Wil-o-dont could be a problem.

Human ultrasonic speech perception.

Bone-conducted ultrasonic hearing has been found capable of supporting frequency discrimination and speech detection in normal, older hearing-impaired, and profoundly deaf human subjects. When speech signals were modulated into the ultrasonic range, listening to words resulted in the clear perception of the speech stimuli and not a sense of high-frequency vibration. These data suggest that ultrasonic bone conduction hearing has potential as an alternative communication channel in the rehabilitation of hearing disorders.

Human skull vibratory patterns in audiometric and supersonic ranges.

The attenuation of bone-conducted stimuli across the human skull was determined in audiometric, ultrasonic, and supersonic frequency ranges (250 to 64,000 Hz). An increase in attenuation with an increase in frequency, as well as significant resonance effects, was observed. For the audiometric frequency range, bone conduction stimulation of one side of the head results in almost equal stimulation of the other side. In the ultrasonic and supersonic ranges, the contralateral side is progressively isolated.

High frequency hearing in jaundiced rats.

All 8 pups in a homozygous-by-heterozygous rat mating were studied using brainstem auditory-evoked responses to clicks and to tone pips at 10, 15, 20, and 25 kc/s. Rats expressing the jaundice trait (N:4) had normal BSAER for click thresholds and latencies of Waves I-IV; however, to tone pips stimulating predominantly the more basal portions of the cochlea. Although thresholds were unaffected, there were mild prolongations of latencies of Waves II-IV representing central conduction time; the prolongation in one jaundiced rat reached significance re controls. Furthermore, amplitude of Waves II-IV to the louder tone pips were about 20% lower for the jaundiced rats. Jaundiced rats may be adequate models for central conduction delay found in human neonatal hyperbilirubinemia when species differences are controlled.

Preyer reflex in jaundiced rats: central auditory effects.

Normal control rats (N:45) and 27 genetically hyperbilirubinemic rats from an NIH colony were tested for the Preyer reflex (Pr) threshold using pure tones. About half of all animals (N:39) were tested at 4, 6, and 8 kc/s only, while 39 were also tested at 10, 15, 20, 25, and 30 kc/s. Data were not included from 3 jaundiced rats who died during the study, which began when Ss were 3 wks old. Some jaundiced rats differed from control rats in their elevated Pr thresholds for mid-frequency tones (approximately 10 kc/s) (group mean threshold difference of 6.4 db (p less than .05). Since jaundiced rats have been shown to have extensive damage in the first brain-stem synapse, neural dysfunction can be inferred. The Pr of jaundiced rats did not differ from normals at frequencies below 10 kc/s. Normal low-frequency sensitivity in jaundiced rats likely represents a tonotopic vulnerability gradient in the central auditory pathway.

Brain-stem evoked response waveform variation associated with recurrent otitis media.

Two cases suggest that long-standing recurrent otitis media contributes to delayed brain-stem evoked response wave III and V latencies persisting after resolution of the otitis media. The persistence of the delayed waves may not reflect structural damage, but rather may still reflect a slowly recovering system.

Effects of spectrum, background noise, and stimulation rate on the auditory startle reflex in hyperbilirubinemic rats.

The sensory element of the acoustic startle reflex was studied in neonatal rats. Stimulus frequency, background noise, and stimulus presentation rate all affected the reflex. The performance of jaundiced rats with central auditory pathology is initially poorer than that of nonjaundiced rats but rapidly improves to the level of the controls, suggesting that the jaundiced rats may be a model for central auditory disturbances in humans. Startle reflex measurements give no indication that jaundiced rats surviving the testing period had neural hearing loss.

Marine turtle middle-ear anatomy.

The middle-ear structures from 5 Atlantic Loggerhead (Caretta caretta) and 1 Atlantic Ridley (Lepidochelys kempi) marine turtles from dead specimens found stranded in the lower Chesapeake Bay were dissected and examined superficially and by light microscopy. The marine turtle middle ear is poorly adapted as an aerial receptor in mammalian and reptilian terms. However, it appears well designed as a peripheral component of a bone conduction system. The thick tympanum, while disadvantageous as an aerial receptor, likely enhances low-frequency bone conduction hearing. The columella directly couples the cochlea and saccule so that its movement would stimulate each end organ. Turtle hearing is probably an integration of both outputs.

Turtle shells as an auditory receptor.

Evoked responses were obtained from the brainstem of seven box turtles (T. carolina) using air conducted stimuli and also vibratory stimuli applied directly to the carapace. Both stimuli elicited similar neural electrical responses that differed chiefly in sensitivity. The vibratory responses were lower in threshold and higher in amplitude than responses to air conducted clicks. Further, simultaneous masking of vibratory clicks by air conducted noise had negligible effects, whereas vibratory masking completely suppressed the responses to airborne sound, suggesting that the turtle ear is differentially sensitive to sound and vibration. Spinal blocking of somatic pathways had negligible effects on the vibratory-evoked responses, suggesting that the latter originate in the auditory system and are stimulated by bone conduction.

Effects of neonatal hyperbilirubinemia on Token Test performance of six-year-old children.

Token Test (TT) performance was investigated of 100 6-yr-old children who had had hyperbilirubinemia as infants. Half these Ss had been given phototherapy for that condition, half had not. Group data revealed that both subgroups performed significantly below the normed average on those sections of the TT that place the heaviest load on short-term auditory verbal memory. Ss who had not been given phototherapy outperformed those who had been given the light treatment. The TT even in abbreviated form (only 15 commands) was a useful tool in identifying short-term memory difficulties in this population. Poor short-term memory performance may predispose these children to difficulties in listening comprehension later in life.

Marine turtle reception of bone-conducted sound.

An individual each of the marine turtles, Caretta caretta and Lepidochelys kempi, were stimulated with audiofrequencies delivered directly to the skull. Startle responses were observed to underwater stimuli of .25 and .5 kc/s. Neural responses to underwater bone-conducted (bc) sound were recorded in another aquatic form, the snapping turtle, Chelydridae serpentina. The morphology of the neural response suggested the involvement of the auditory system in bc responsivity. Bc hearing appears to be a reception mechanism for marine turtles with the skull and shell acting as receiving surfaces. Turtles are capable of receiving the low-frequency spectrum of the natal beach, which may serve as one of the cues in nesting returns.

Shallow-water propagation of the toadfish mating call.

A mismatch between sound production and hearing in the oyster toadfish, Opsanus tau L., suggests the hypothesis that toadfish communicate over short distances. Low frequency acoustic signals (tones, noise and toadfish courtship calls) broadcast in 1 m deep water, attenuated rapidly, thereby restricting communication within a range of only several meters. Ambient noise does not appear to exert a strong selection pressure on the frequency spectrum of the boatwhistle or on the distance over which it is audible.