Usage of personal music players in adolescents and its association with noise-induced hearing loss: A cross-sectional analysis of Ohrkan cohort study data.

OBJECTIVE: To describe personal music player (PMP) usage among adolescents, sociodemographic determinants and association with audiometric notches. DESIGN: Audiometric evaluation to assess hearing status, and standardized questionnaires to evaluate PMP listening behaviors, leisure noise exposures and self-reported hearing loss symptoms. Sociodemographic information was collected using a parent questionnaire. Noise exposure by PMP usage equivalent for a 40 h week was estimated based on self-reported volume and duration of use. STUDY SAMPLE: A total of 2143 students (54% females) attending 9th grade in Regensburg, Germany, during 2009 to 2011. RESULTS: Overall, 85% of the students reported using PMPs. Exposure level exceeded 80 dB(A) in approximately one third, and 85 dB(A) in one quarter, of those who used PMP. An audiometric notch was found in 2.3% of participants, but was not significantly associated with higher PMP exposure. CONCLUSIONS: PMP exposure above the occupational limits of 80 and 85 dB(A) set by the Directive 2003/10/EC may be a risk factor for developing noise-induced hearing loss. Educational measures to ameliorate high risk behaviors in PMP usage are needed, particularly for socially disadvantaged groups.

Early indication of noise-induced hearing loss from PMP use in adolescents: A cross-sectional analysis.

CONTEXT: Distortion product otoacoustic emissions (DPOAEs) may indicate preclinical noise-induced hearing loss (NIHL) in adolescents from unsafe personal music player (PMP) use. AIMS: The objective, therefore, was to observe preclinical signs of NIHL in 9th grade adolescents with clinically normal hearing by comparing DPOAE signals between different levels of A-weighted equivalent PMP exposure. SETTINGS AND DESIGN: Subjects were recruited from all secondary-level schools located in the city of Regensburg, Germany during two academic years 2009/2010 and 2010/2011. SUBJECTS AND METHODS: A-weighted equivalent sound pressure levels (SPLs) for a 40-hour work week (LAeq,40h) were estimated from questionnaire responses on output and duration of PMP use of the previous week. Subjects were then categorized into four levels of exposure: <80, 80-85, >85 to <90, and ≥90 A-weighted Decibel [dB(A)]. DPOAE signals were collected by trained audiological staff, applying a standard optimized protocol, at the Department of Otorhinolaryngology of the University Hospital Regensburg. STATISTICAL ANALYSIS USED: Mean DPOAE signals were compared between levels by unpaired t test. Novel linear regression models adjusting for other leisure noise exposures and with outcome variables DPoutcome and 4 kilo Hertz (kHz) DPOAEs estimated effects between levels. RESULTS: A total of 1468 subjects (56% female, mostly aged 15 or 16 years) were available for analysis. Comparison of DPOAE means by PMP exposure typically showed no greater than 1 dB difference between groups. In fact, comparisons between ≥90 dB(A) and <80 dB(A) presented the least differences in magnitude. Both DPoutcome and 4 kHz linear regression models presented a weak association with the 4-level PMP exposure variable. An expected dose-response to PMP exposure was not observed in any analyses. CONCLUSIONS: DPOAE signal strength alone cannot indicate preclinical NIHL in adolescents.

Total leisure noise exposure and its association with hearing loss among adolescents.

OBJECTIVE: To investigate total leisure noise exposure among adolescents and to assess its association with hearing. DESIGN: Based on self-reported time spent on 19 leisure activities and associated mean sound pressure levels reported in the literature, total leisure noise exposure was evaluated and compared to noise at work limits (> 85 dB(A) = hazardous) in a cross-sectional survey. Tympanometry and pure-tone audiometry was performed in sound isolated rooms. STUDY SAMPLE: The study sample consists of 2143 pupils attending grade nine in any school in a German city 2009-2011 (mean age: 15.4 years; range: 13-19 years). Audiometric data were available for 1837 (85.8%) pupils (53.9% girls). RESULTS: 41.9% of the 2143 adolescents who had provided self-reported data on leisure activities associated with noise exposure were estimated to be hazardously exposed to leisure time noise. The interaction of gender with total leisure time noise exposure was not significant. No association between leisure time noise exposure and audiometric notches could be detected. CONCLUSION: While hearing loss seems seldom in this age group, a high proportion of adolescents aged 15-16 years are exposed to noise levels during leisure time bearing long-term risks of hearing loss.

The prevalence of audiometric notches in adolescents in Germany: The Ohrkan-study.

Although there is concern about increasing hearing loss in adolescents caused by leisure noise exposure, prevalence data are scarce. In an US study, about 16-17% of adolescents were affected by audiometric notches. To estimate the prevalence of audiometric notches in adolescents in Germany, baseline data of the cohort study Ohrkan, recruitment during the school years 2009/2010 and 2010/2011 were analyzed. All students in grade 9 visiting any school in the city of Regensburg were eligible for participation. Data was collected via standardized questionnaires from students and their parents. In addition, students were asked to visit the University Clinics of Regensburg for ear examination including a tympanogram and the determination of hearing thresholds in air conduction audiometry. The prevalence of audiometric notches was determined in students with normal tympanogram in both ears and complete audiometry data. Audiometric notches were defined according to criteria used to analyse US data. Overall, 2149 students (1158 girls, 991 boys mainly aged 15-16 years) of the 3846 eligible adolescents (56%) participated. Among the 1843 adolescents with complete audiometry and tympanometry data, the prevalence of audiometric notches was 2.4% (95% confidence interval 1.7-3.1%). We could not confirm the high prevalence of audiometric notches as reported in National Health and Nutrition Examination Surveys for adolescents in the US. Differences in prevalence might be at least partly due to methodical differences in audiometry. Even if empirical evidence is presently ambiguous, it is reasonable to educate young people about the potential risks of high leisure noise exposure.

Concentrations of polybrominated diphenyl ethers, organochlorine compounds and nitro musks in mother's milk from Germany (Bavaria).

The aim of this study was to determine a new spectrum of substances that will be selected for future breast milk monitoring in Bavaria, Germany. Up to now, the analysis of breast milk in Bavaria was limited to selected organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB). Information on background levels of toxicologically interesting substances, such as dioxins and dioxin-like polychlorinated biphenyls (dl-PCB) or on flame retardants, such as polybrominated diphenyl ethers (PBDE) are very limited or not available for Bavaria. We present here levels on OCP, some nitro musks, indicator PCB, polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and dl-PCB concentrations in breast milk collected at 12 weeks post-partum of 43 primiparous mothers living in Bavaria. The average concentrations of PCDD, PCDF and dl-PCB were 4.98, 4.93 and 9.92 pg WHO-TEQ g(-1) lipid, respectively. The mean contribution of PCDD, PCDF, non-ortho and mono-ortho PCB to the total WHO-TEQ is consistently about 25% each. Furthermore the concentration on PBDE in breast milk at two sampling points, 12 weeks and 16 weeks after delivery, were determined. Overall, 19 PBDE congeners were analysed, however the level of 12 PBDE congeners were below the limit of detection. BDE-153 and BDE-47 were the predominant congeners accounting for about 66% of the total PBDE. The means of the total concentrations of PBDE (five congeners) at the first and second sampling point were 1.90 and 2.03 ng g(-1) lipid, respectively. Based on our results the overall concentrations of the analysed substances in milk samples from Bavaria are consistent with the levels of breast milk samples of other European countries reflecting the low background body burden of these compounds.

Bavarian breast milk survey--pilot study and future developments.

For more than 20 years the Bavarian Health and Food Safety Authority has carried out breast milk analyses of persistent pesticides and selected organohalogen compounds. On the one hand, continuous monitoring of the levels of these chemicals in human breast milk shows a decreasing trend over these two decades. On the other hand, the number of samples sent to our institution for analysis has continuously decreased. Given the unreliable data on burden of environmental chemicals as well as the toxicologically outdated spectrum of analyzed substances, a new concept for the monitoring of breast milk has been developed and tested within a pilot study. We present here first results on PCDD, PCDF and dioxin-like PCB (dl-PCB) concentrations in breast milk of 43 women living in Bavaria, Germany. The average concentration of PCDD, PCDF and dl-PCB were 4.93, 4.98 and 9.92 pg WHO-TEQ/g fat, respectively. The new surveillance program (Bavarian Monitoring of Breast Milk, BAMBI) should track time trends of chemicals' concentrations in breast milk, while also monitoring new chemicals, such as PBDE or PFC, on which little or no German data exist.

Prevalence of and risk factors for carriage of Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus among residents and staff of a German nursing home.

The aims of this cross-sectional study were to determine the prevalence of and risk factors for carriage of Panton-Valentine leukocidin-producing methicillin-resistant Staphylococcus aureus (PVL-MRSA) in residents and personnel of a nursing home in Germany. In this study, PVL-MRSA carriage status among nursing home residents was associated with risk factors reflecting their dependence on nursing care. No specific risk factors were detected among staff.

Organochlorine compounds, nitro musks and perfluorinated substances in breast milk - results from Bavarian Monitoring of Breast Milk 2007/8.

The aim of the Bavarian Monitoring of Breast Milk (BAMBI) project was to examine 10 organochlorine pesticides (OPs), 3 nitro musks, 6 indicator polychlorinated biphenyls (PCBs), 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like PCBs (dl-PCBs) and several perfluorinated alkyl compounds in breast milk samples. A total of 516 breast milk samples were collected from seven regions in Bavaria and were analyzed by means of GC/ECD, GC/HRMS, and LC/MS-MS. Concerning the OPs, only hexachlorobenzene and a metabolite of DDT, 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (p,p'-DDE), could be quantified in all samples (median: 16 ngg(-1) lipid and 63 ngg(-1) lipid, respectively). Median concentrations of 150 ngg(-1) lipid (range: 3-1900 ngg(-1) lipid) were found for the sum of the indicator PCBs. The concentrations of the PCDDs/PCDFs and the dl-PCBs ranged from 0.8 to 15.1 (median 5.7) pg WHO-TEQ1998g(-1) lipid and from 1.5 to 18.9 pg (median 6.4) WHO-TEQ1998 g(-1) lipid, respectively. The median perfluorooctane sulfonate concentration was 0.05 µgL(-1) (range: <0.02-0.26 µgL), while the other PFCs were observed only in a subset of samples. On the basis of the median and 95th percentile concentration, "medium" and "high" intake levels were estimated for a 3-month-old exclusively breastfed infant. In particular, "medium" and "high" intake levels were calculated of 69 and 133 pg WHO1998 TEQ kg(-1) b.w. for PCDDs/PCDFs, 8 and 21 ngkg(-1) b.w. for dl-PCBs, and 6 and 25 ngkg(-1) b.w. for perfluorooctane sulfonate, respectively. The calculated intake for perfluorinated substances is clearly below the tolerable daily intake (TDI), while the established TDI values are still clearly exceeded for PCDDs/PCDFs and dl-PCBs.

Recurrent high level parvovirus B19/genotype 2 viremia in a renal transplant recipient analyzed by real-time PCR for simultaneous detection of genotypes 1 to 3.

Organ transplant recipients infected with parvovirus B19 frequently develop persistent viremia associated with chronic anemia and pure red cell aplasia. In this study, a male renal transplant recipient who had been infected with parvovirus B19/genotype 2 after renal transplantation at the age of 34 years is described. The patient was repeatedly treated with high dose intravenous immunoglobulin (IVIG) that resulted in the resolvement of symptoms but not in virus eradication. During an observation period of 33 months after transplantation three phases associated with high parvovirus B19 viremia were observed. Both the first and the second viremic phases were combined with severe anemia. Parvovirus B19 specific IgM-antibodies were initially detected at the beginning of the second phase in continually rising concentrations. Initially eradication of the virus by immunoglobulin therapy was reported after the first viremic phase [Liefeldt et al. (2002): Nephrol Dial Transplant 17:1840-1842]. Retrospectively this statement has to be corrected. It was based on the use of a qualitative PCR assay specific for parvovirus B19 genotype 1 associated with reduced sensitivity for detection of genotype 2. After sequence analysis of the viral DNA and adjustment of a real-time PCR assay (TaqMan) for quantitative detection of all three B19 virus genotypes analysis of consecutive serum samples allowed the demonstration of long lasting phases with reduced viral loads following IVIG-treatment. These results demonstrate that IVIG treatment of parvovirus B19-triggered anemia in transplant recipients offers an opportunity to resolve symptoms, but does not guarantee eradication of the virus. Since reactivation of parvovirus B19 infection can result in high virus load associated with the recurrence of symptoms repeated screening for viral DNA is recommended using the TaqMan system established for quantitative detection of all three genotypes of parvovirus B19.

Cellular transcription factors that interact with p6 promoter elements of parvovirus B19.

All transcripts of the human parvovirus B19 identified so far are regulated by a single promoter at map unit 6 of the viral genome, the so-called p6 promoter. This promoter is active in a wide variety of different cells. In order to identify cellular transcription factors involved in regulating promoter activity, we performed gel-retardation and supershift assays using the parts of the p6 promoter sequence shown previously to be protected in footprint experiments. Thereby, binding was demonstrated of the Oct-1 protein to an octamer motif within the p6 promoter and of the transcription factor Sp1 to three GC boxes. A specific preferential interaction of the factor Sp3 with one of these boxes was observed, indicating that the ratio Sp1:Sp3 may be involved in the regulation of promoter activity. Consensus sites for the regulatory protein YY1 are located close to the GC boxes and the octamer motif, to which this factor binds efficiently.

NS1 protein of parvovirus B19 interacts directly with DNA sequences of the p6 promoter and with the cellular transcription factors Sp1/Sp3.

The nonstructural proteins of parvovirus exert a variety of disparate functions during viral infection ranging from promoter regulation, involvement in DNA replication, and induction of apoptosis. Our interest was focused on the possible mechanism by which the NS1 protein mediates its effects on the p6 promoter of parvovirus B19. It is known that the p6 promoter is highly active in different cell lines and interaction with the viral NS1 protein results in a further increase of the activity. The protein may function by binding directly to the viral DNA or via an indirect binding through interaction with cellular transcription factors bound to the promoter. We examined the interaction of the NS1 protein with cellular transcription factors which are involved in regulating the promoter activity. After purified baculovirus-expressed NS1 protein in gel retardation assays was added, an altered complex formation was observed, indicating that NS1 protein interacts with Sp1/Sp3 transcription factors. Enzyme-linked immunosorbent assays verified these findings. The direct interaction of NS1 protein with p6 promoter elements was analyzed by a coprecipitation assay whereby labeled oligonucleotides spanning the entire promoter region were incubated with NS1 protein followed by an immunoprecipitation with NS1-specific antibodies. An eight-nucleotide-long, almost palindromic sequence (AGGGCGGA) was found as potential NS1-binding motif. Footprint analysis with oligonucleotides containing this DNA motif confirmed this result. Thus, transcriptional regulation by the NS1 protein may involve both the interaction with Sp1/Sp3 that binds to the promoter region and direct binding of NS1 to the promoter DNA.