A comparison of audiometric and objective methods in hearing screening of school children. A preliminary study.

OBJECTIVE: In newborn hearing screening, one exclusively applies objective hearing testing methods--based on evoked potentials and/or on otoacoustic emissions. However, when testing school children, one can consider both audiometric and electrophysiological methods. The choice of methods is determined by the aims of the program. If one wants to detect conductive hearing losses, impedance audiometry seems to be the method of choice. METHODS: The aim of this study was to compare test performance measures from audiometric and objective methods (OAEs and impedance audiometry), in the hearing screening of school children. Screening protocols were applied on a group of 190 children of about 12 years of age (6th grade of primary school). RESULTS: For a single application of a screening procedure, the best performance was observed in the automated four-tone audiometry, followed by the tympanometry and the TEOAE-based procedures. Screening performance was enhanced using a combination of automated and impedance audiometry. A four-tone audiometry test combined with tympanometry gives a sensitivity of 65%, and the PPV of 46%, which are reasonable values, acceptable for practical use. The use of a TEOAE protocol degrades the overall performance of screening. CONCLUSIONS: Screening of school children is feasible with a combination of automated audiometry and tympanometry with time requirements equal to 3 min per subject.

Evaluation of cell membrane integrity of spermatozoa by hypoosmotic swelling test - "water test" in mice after intraperitoneal daidzein administration.

The functional integrity of the cell membrane of the mice sperm after daidzein administration intraperitoneal was assessed by studying the swelling reaction of the sperm when suspended in distilled water. The results obtained in water test indicate that daidzein, one of the phytoestrogens, decreases the number of normal and live sperm (swollen) in the samples obtaining from vas deferens. This effect was statistically significant in the mice after 7 and 14 days of daidzein administration. In mice treated with daidzein the number of dead (unswollen) sperm was increased, especially in animals after 14 days of experiment.

Sulfurtransferases and cyanide detoxification in mouse liver, kidney, and brain.

The activity of rhodanese, 3-mercaptopyruvate sulfurtransferase (MPST) and cystathionase in mouse liver, kidney, and four brain regions: tele-, meso-, di- and rhombencephalon was studied 30 min and 2 h following a sublethal dose of cyanide (4 mg/ kg body weight) intraperitoneal injection. Simultaneously, sulfane sulfur levels and total sulfur content, a direct or indirect source of sulfur for CN(-) conversion to SCN(-), were also investigated in these tissues. In the liver this dose of cyanide seemed to impair the process of cyanide detoxification by MPST, as well as rhodanese inhibition. The effects of cyanide administration to mice proved to be totally different in the liver and kidney. In the kidney, a significant increase in the rhodanese activity was observed as early as 30 min following cyanide intoxication, and an elevated cystathionase activity after 2 h was detected. This suggests the involvement of cystathionase in cyanide detoxification in the kidney. The activity of MPST remained at the same level as in the control group. In the rhombencephalon, similarly as in the kidney, L-cysteine desulfuration pathways, which generate sulfane sulfur and sulfurtransferases that transfer sulfane sulfur atoms to CN(-), seemed to play an important role as a defense system against cyanide. The stable level of sulfane sulfur and total sulfur content was accompanied in the rhombencephalon by an increased activity of MPST, cystathionase and rhodanese. In other brain regions the role of these three sulfurtransferases was not so clear and it seemed that in the telencephalon, where the total sulfur content, but not the sulfane sulfur level, was significantly increased, some sulfur-containing compounds, such as GSH and/or cysteine, appeared in response to cyanide.

Effect of transforming growth factors (TGFalpha and TGFbeta) on human sperm chemotactic migration in vitro.

The effect of transforming growth factors (TGFalpha and TGFbeta) on mouse sperm motion chemotactic behavior was examined. In an in vitro model, the number of mouse sperm cells migrating to medium containing TGFalpha in concentration 500 ng/mL were significantly higher than the number migrating to control. This effect was observed after 3 and 5 h of incubation. The presence of 100 ng/mL of TGFalpha and TGFbeta in concentration 100 and 500 ng/mL in incubation fluid did not cause any statistically visible changes on the migration of sperm. Effect of combination of both cytokines was similar to influence purely TGFalpha. These effects were interpreted as chemotaxis but not chemokinesis of sperm induced by influence of this cytokine on membrane receptors. It is suggested that of TGFs contained in follicular fluid plays a direct and important role in the process of mammalian fertilization.

Mutations in bacteriophage T4 genome.

Bacteriophage (phage) T4 belonging to T-even phages is one of the best known phages with a completely deciphered genome sequence. As a model of living systems, T4 phage has many technical advantages. It can be very easily grown in large quantities, manipulated by classical genetics, and engineered by site-directed mutagenesis. Many substances have been first tested for mutagenicity in T-even phages. The results of these tests were very often applicable to higher organisms due to similar mechanisms of mutagenesis. T4 phage is also important in phage therapy, which represents an alternative treatment of bacterial infections since the bacterial resistance to antibiotics has become a serious medical problem. The site-directed mutagenesis is a method that enables to introduce mutations which can influence phage affinity to bacteria and can be a practical technique for enriching phage collections and for widening specificity of phages for new bacterial strains now insensitive to phage therapy.

[Effect of hormones on biological properties of spermatozoa]. / Wplyw hormonów na biologiczne wlasciwosci plemników.

The paper presents a review of the most important literature dealing with direct influence of hormones on basic biological properties of the mammalian spermatozoa, e.g. motility, chemotaxion and acrosome reaction. Original data from the author's own research, are also provided. Spermatozoa have active receptors for many hormones thus their metabolism and behavior can be epigenetically modified. Hormones of semen, reproductive tract and ovarian follicle liquids are able to influence sperm motility as well as their chemotactic movements. Hormones assist the acrosome reaction in inducing ion transport in spermatozoa. These properties are not only the features of hormones found in spermatozoan natural environment, but there are also other hormones, which have rather pharmacological then physiological effect.

Substance P and beta-endorphin act as possible chemoattractants of mouse sperm.

The effect of beta-endorphin and substance P on mouse sperm motion was examined in an in vitro model. The number of mouse sperm cells migrating to mediuin containing substance P in pharmacological concentrations of 5, 25, and 50 ng/mL were significantly higher than the number migrating to control. This effect was observed after 3 h at a concentration of 5 ng/mL and 1 h at 25 and 50 ng/mL. Demonstrated changes in spermatozoa behavior in the presence of substance P were time and concentration dependent. These effects were interpreted as chemotaxis but not chemokinesis of sperm induced by influence of this tachykinin on membrane receptors. The presence of beta-endorphin in incubation fluid in concentrations of 5, 25, and 50 ng/mL did not cause any visible changes or decrease sperm migration. Substance P contained in follicular fluid played a direct and important role in the process of mammalian fertilization.

[The effect of melatonin on directional motility of human sperm under in vitro conditions]. / Wplyw melatoniny na kierunkowe przemieszczanie sie plemników czlowieka w warunkach in vitro.

In model experiments carried out in vitro, human spermatozoa move in well-ordered manner following the concentration gradient. Such behavior is called sperm chemotaxis. The investigations with use of melatonin indicate that this hormone, contained in the follicular liquid, cannot be regarded as chemotactic substance for human spermatozoa. Melatonin in concentrations of 1 mM and 10 mM respectively, do not influence the sperm behavior, however in concentration of 20 mM inhibits their movements in canals of incubation chamber, i.e. shows chemorepelent effect.

Effect of sodium nitroprusside on mouse sperm migration in vitro.

In the present study the effect of sodium nitroprusside, a nitric oxide releaser, on mouse sperm motion behavior was examined. The number of sperm migrating in experimental plate to medium containing sodium nitroprusside in concentration 50 nM was significantly higher than the number migrating to control. This effect was observed after 3 and 5 h of incubation, and it was not time dependent. The presence of sodium nitroprusside in higher concentrations did not cause any visible changes or decrease the migration of sperm. These effects were interpreted as chemokinesis but not chemotaxis of sperm induced by influence of sodium nitroprusside on sperm metabolism and motility.

Hyaluronic acid and chemoattractant substance from follicular fluid: in vitro effect of human sperm migration.

The glycoaminoglycans hyaluronic acid (HA) has been described in human follicular fluid and its effect on spermatozoa motility was previously described. In an in vitro model, the number of human spermatozoa migrating to wells containing HA was significantly higher than the number migrating to control wells. Time- and concentration-dependent effects of HA on directional migration of spermatozoa indicate a chemotactical character of observed phenomenon.

Chemotaction of mouse spermatozoa induced by certain hormones.

Chemotaxis assays of mouse spermatozoa were performed in vitro. Amounts of calcitonin (5.0 IU/ml, 10.0 IU/mL) and acetylcholine (1.0 mg/ml) in Biggers-Whitter-Whittingham medium filled out wells of experimental plate were increased directly by migration of mouse spermatozoa to the medium containing these hormones. This effect was interpreted as chemotaxis of spermatozoa. Low concentrations of hormones were not attractants and high concentrations of acetylcholine (5.0 mg/mL) decreased spermatozoa migration. Glucagon and vasopressin results in a decrease in concentration of migrated spermatozoa. In low concentrations of these hormones differences in sperm migration were not observed. Presence of histamine and thyroxine in BWW medium did not affect the migration behavior of mouse spermatozoa in vitro.

Effect of some sex steroid hormones on human spermatozoa migration in vitro.

The potential chemotactic effect of sex steroid hormones on human spermatozoa was studied. In an in vitro model, the number of human sperm cells migrating to Biggers-Whitten-Whittingham (BWW) medium containing progesterone in concentrations from 1 microgram/ml to 100 micrograms/ml was significantly higher than the number migrating to control medium (pure BWW). The presence of testosterone in the incubation medium decreases the migration of spermatozoa, and estradiol and estriol did not cause any visible changes in their behaviour. This effect of changes in migration was interpreted as chemotaxis of spermatozoa.

Effects of selected hormones on the motility of spermatozoa in the mouse vas deferens.

Acting in vivo, adrenalin and noradrenalin cause a statistically significant and permanent decrease in the motility of mouse spermatozoa remaining in the vas deferens. Intratesticular injection of vasopressin, oxytocin, insulin, and glucagon results in a decrease in spermatozoa motility in vas deferens, removal the spermatozoa to PBS in vitro, and an increase in percentage of motile spermatozoa on incubation medium. Thyroxine, calcytonin, and TRH did not affect motility of mouse spermatozoa in vivo.

Chemotactic effect of hormones in mouse spermatozoa.

In an in vitro model, the number of mouse sperm cells migrating to wells containing adrenalin (0.001 mg/mL) and oxytocin (0.01 IU/mL) was significantly higher than the number migrating to control wells. This effect was interpreted as chemotaxis of spermatozoa. The presence of insulin in BWW medium decreased the concentration of spermatozoa in experimental migration in vitro.

Effect of heparin on human spermatozoa migration in vitro.

In an in vitro model, the number of human sperm cells migrating to wells containing heparin was significantly higher than those migrating to control wells. In humans a statistically significant chemotactic effect was noted in a 0.05 mg/ml in incubation medium.

Usability of the hypoosmotic swelling "Water-test"--a simple method to assess sperm membrane integrity in mouse spermatozoa.

The functional integrity of the membrane of sperm from 3 strains of mice (BALB/c, CBA/KW, and C57BL/KW) was assessed by studying the swelling reaction of the sperm when suspended in a medium of distilled water. The results were correlated with analysis of sperm motility and those of Eosin-Y staining. The results obtained from the Eosin-Y test and "Water-test" differed (P < 0.01) between strains C57BL/KW and both BALB/C, and CBA/KW. A good correlation was observed in all strains of mice between the values of the "Water-test" and those for Eosin-Y staining (P < 0.01).

Wplyw rodzaju bodzca dzwiekowego na oznaczanie progu slichowego metoda ABR. [The effect of brief tone envelopes on ABR and behavioral thresholds].

The present study examines the effect of brief tone envelopes on ABR and behavioral thresholds in small groups of normal and hearing-impaired subjects. The hearing-impaired subjects had very steep high-frequency hearing loss in 2-6 kHz region. The stimuli for both ABR and behavioural estimates were 2 and 4 kHz tone burst with linear and nonlinear envelopes. Behavioural thresholds were estimated using a computer controlled, modified block up-down method. The ABR thresholds were evaluated from the recordings collected in automatic acquisition process. Results of our experiments showed that for different stimulus envelopes both behavioural and ABR thresholds were similar in normal range of hearing. However, for impaired ears at high frequencies, both psychoacoustic and ABR thresholds differ, sometimes quite significantly, depending on stimulus envelope.

Effect of heparin on the motility of spermatozoa in the mouse vas deferens.

Acting in vivo, heparin causes a statistically significant and permanent decrease in the motility of mouse spermatozoa remaining in the vas deferens. This effect was observed after intratesicular injection of 0.1 mg of heparin.

The effect of selected amino acids on in vitro motility of mouse sperm.

The effect of glutamic acid, alanine, glycine, arginine, leucine, and cystine on the motility of mouse sperm was investigated. In comparison with the control, sperm motility was increased only following incubation in glutamic acid at a concentration of 0.05 mg/ml, concentrations of 0.25 mg/ml and 1.00 mg/ml decreasing the motility of spermatozoa. Alanine, glycine, arginine, and leucine at all concentration used decreased the percentage of motile sperms, while cystine did not cause any visible changes in their motility.